Estuarine Ecology

The southern distributional limit for mangroves on the east coast of Africa is thought to be at the planted mangrove forest at Nahoon Estuary (33° S) in the Eastern Cape, South Africa. This study investigated the influence of a tidal creek on the intertidal zone and the physical and biological differences between the salt marsh and mangrove forest communities at Nahoon Estuary. Three transects were established across the tidal creek and one transect in each of the following habitats mangrove, mangrove–salt marsh, and the salt marsh area. The tidal creek introduced oxygenated (~ 6 mg.l −1) and saline water with high levels of total suspended solids (120–424 g.l −1) into the intertidal zone. In areas where tidal water was retained, algal mats formed over pneumatophores during summer. The vegetation distribution in the mangrove–salt marsh community was significantly affected by elevation, ammonium concentration, and porewater temperature while the salt marsh vegetation distribution was influenced by porewater salinity, sediment, pH and the percentage of sand content. Porewater nitrogen was mostly present as ammonium, and phosphate concentrations were moderate ranging from 1.3 μM in the salt marsh to 3.7 μM in the mangrove community. Mangrove and salt marsh communities are clearly constrained by the physical characteristics of the intertidal area (elevation) and this will ensure that both communities will be maintained at Nahoon Estuary. However with climate change and sea level rise, this may change in the long term with mangroves expanding into elevated areas.

The use of hydraulic geometry and other geomorphic indices has been recommended for habitat restoration
and creation of estuarine tidal channels. Although such an approach provides design guidance for tidal channel form, it
does not provide guidance for the ecological consequences of channel form. This study investigates the potential linkage
of the scaling of tidal channel form with ecological patterns and processes in estuarine tidal channels of the lower
Chehalis River, Washington, U.S.A. Ebb tide surface velocity was related to channel size, as was exit time and export
probability of tiny drogues, which mimic floating allochthonous detritus. Consequently, the amount of organic material
in channel sediments scaled negatively with channel size as did the abundance of benthic surface deposit feeders.
These observations suggest that the highest concentrations of fish feeding in estuarine tidal channels may be in smaller
channels or in the smaller and more distal portions of large channels. Scaling of ecological patterns and processes with
tidal channel size may be an example of a more general ecological scaling with landscape form, i.e., landscape
allometry.

This memo is the result of an exploration of possible sources on the Eastern Scheldt estuary. The memo’s aim is to provide a clear point of departure for the Eastern Scheldt Survey, which will summarize up to date knowledge on the Eastern Scheldt Barrier and its effects.
It offers the opportunity for the Severe Storm Prediction Education and Evacuation from Disasters-center (SSPEED), the commissioner of the Survey, to give further direction to the search if required.
Being the product of much public and expert debate, the barrier and the estuary have enjoyed much attention over the last decades, resulting in numerous publications addressing a variety of topics. The findings of the exploration of these sources are grouped in three categories: (1) decision-making regarding the construction of the barrier, (2) the environmental effects, and (3) the effect on the regional spatial-economic development pattern. Within these categories, the following themes were studied:
i. Public and expert debate before, during and after construction (and its effect on policy and decision-making)
ii. Effects on hydrodynamics, sediment fluxes and morphology
iii. Effects on benthos and primary production
iv. Effects on wading birds
v. Mitigation measures
vi. Economy
vii. Land use development pattern

Estuaries and coastal lagoons around the world are wetlands of great
importance and they are regularly targeted as prime conservation sites.
Many include wildlife refuges and have nature reserves that were set up in
areas preserved from development in order to keep valuable species and
habitats, while maintaining traditions and sustained use.
Tidal wetlands are often mentioned in the literature as natural habitats
with high biological productivity. The net primary production in a salt
marsh is often higher than in temperate or tropical forests and this productivity
is directly linked to the important role halophytes play in estuaries,
in terms of the value-added.
Salt marshes may be a sink of heavy metals. The ability to phytostabilize
contaminants in the rhizo-sediment is an important aspect in the selfremediative
processes and biogeochemistry of this ecosystem, and will
help fi ltering natural and anthropogenic loads of nutrients and pollutants
discharged into the wetland.
There is also a provision of rare and unique habitats, which support nursery
grounds for commercial fi sh and wildlife, including vital feeding grounds
for many migratory birds. Rediscovered as a new source of amenity and leisure
activities for the population living in urban areas, salt marsh halophytes
and estuaries have an important role in the preservation of biodiversity.
In this paper we discuss the support of the salt marsh ecosystem to the
estuarine birds, and consequently its contribution for biodiversity.

The aim of this survey is to give a concise overview of the pre- and post-barrier functioning of the Eastern Scheldt estuary. The survey builds upon the Eastern Scheldt Memo (dated March 2016), which explored possible sources and shortlisted leading publications, key institutes and contacts. In response to the memo’s reception by the commissioner of this study, the Severe Storm Prediction Education and Evacuation from Disasters (SSPEED)-centre, the survey has focused on two fields of interest:
1. The first field targets key environmental changes in the estuary after 1986. These have been grouped under five main categories: hydrodynamics, morphology, benthos & primary production, fish & aquaculture, and wader bird population. These include topics like salinity, channel alignment and (re)location of aquaculture plots.
2. The second field describes contemporary management- and mitigation efforts aimed to preserve the functioning of the estuary’s ecosystem.

For a full view, the two parts of this study are to be read in concert, as the survey (part 2) only elaborates on selected issues from the memo (part 1).

Long-term assessment of ecosystem restoration projects is complex because of ecological processes such as succession, particularly in highly dynamic ecosystems such as estuaries. Restoration of intertidal flats and marshes on formerly embanked land, often called managed coastal realignment (MR), became popular in estuarine management. In our study, biophysical and monetary data were collected to calculate the value of 15 (sub)ecosystem services (ES) delivered by a large tidal marsh restoration project in the Schelde estuary in Belgium and the Netherlands. We hypothesized that ES delivery changes over time due to ecological succession and hence the long-term benefits are subject to this phenomenon and need to be taken into consideration. A marsh sediment accretion model (MARSED) was used to simulate potential marsh succession scenarios. In this way, the temporal evolution of ES delivery caused by ecological succession could be evaluated. Our study shows that benefits during successional marsh stages could actually be higher than for marshes in equilibrium. This finding does not suggest that ecosystems in transition always have a higher value than systems in equilibrium, but emphasizes the need to consider long-term ecological dynamics, such as succession, in a benefit assessment for restoration projects.

The diversity of benthic macroinvertebrates in the Upper (Zone 1) and Middle Thames Estuary (Zone 2) and its associated tributaries, creeks and dock basins was studied using the commonly used hand picking, kick-sampling, core-sampling and wall scraping (barking) methods to examine diversity similarity and differences in macroinvertebrates assemblages between them. Population densities, species lists, densities diversity, and similarity measures were used to analyse the macroinvertebrate dataset obtained from the sorting, identification and counting of the invertebrate species. Results suggested that the upper estuary sites produced the largest number of species/families and middle estuary and creek sites produced the largest number of individuals but the lowest number of species. The Royal dock basins had specialised benthic invertebrate groups, whilst the East India Dock basin had benthic macroinvertebrates composition similar to that of the main river. The mudflat of the mid estuary creeks display very high abundances and dominances by oligochaete and polychaete worms; and their central channels by freshwater species (mainly of upstream of the tributary origin). The study also indicated that habitats with similar physical and other environmental conditions yielded similar macroinvertebrate assemblages.

A pesca de Penaeus paulensis no estuário da Lagoa dos Patos atua sobre uma importante área de criação e crescimento para grande parte dos peixes e crustáceos comercialmente explorados no sul do Brasil. Este trabalho avalia o impacto da pesca com o "aviãozinho" sobre a ictiofauna do estuário da Lagoa dos Patos. Foram analisadas 53 amostras obtidas em 33 visitas a dois pontos de desembarque durante as safras de 1993/94 e 1994/95. Como unidade de esforço de pesca foi considerado o número total de redes "aviãozinho" utilizadas por cada pescador em um dia de pesca (12 horas efetivas). Uma estimativa do esforço de pesca para todo estuário foi feita a partir da avaliação da intensidade de pesca (redes/Km2/dia) de uma área conhecida. Do total capturado em peso o camarão-rosa representou em média 66,7%, os siris do gênero Callinectes 26,8% e os peixes 6,6%. A rejeição na pesca com o "aviãozinho" é constituída, basicamente, por peixes juvenis de pequeno tamanho. Micropogonias furnieri (corvina) e Netuma barba (bagre-marinho) foram as espécies dominantes na rejeição, tanto em número quanto em peso, constituindo as espécies mais potencialmente impactadas. Com base na estimativa de cerca de 15.866 redes/dia atuantes em todo estuário estima-se que o rejeito total de peixes na safra de 1994/95 tenha sido da ordem de 445,9 t, sugerindo um nível de impacto considerável desta atividade sobre as populações que compartilham o ambiente estuarino. O resultados mostram-se, contudo, mais alarmantes quando as capturas são expressas em número. Micropogonias furnieri teve um CPUE geral de 2,2 ind./rede que, ponderado pelo número de redes atuantes e a duração da safra, resulta em 4,2 milhões de indivíduos juvenis capturados por safra. Para N. barba, com um CPUE de 1,4 ind./rede, o valor é de 2,7 milhões de indivíduos juvenis por safra. Conclui-se que a pesca com o "aviãozinho" representa um impacto sobre estas populações, sendo necessário um controle efetivo do esforço de pesca sobre o camarão-rosa no estuário da Lagoa dos Patos.

The fishery of Penaeus paulensis on the Lagoa dos Patos estuary takes place on an important nursery ground for many fish species exploited on southern Brazil. Although caught by various fishing gears, the pink shrimp fishery in the estuarine zone is only allowed with passive nets (e.g., "aviãozinho"), which are the most used by artisanal fisherman. This work makes an impact assessment of the "aviãozinho" fishery over the fish fauna that inhabit the Lagoa dos Patos estuary. Samples (53) were obtained in 33 visits on two landing points during 1993/94 and 1994/95 fishing seasons. Fish species were classified according to its frequency in the samples and the percentual contribution in weight and number in the catches. As unit of fishing effort it was considered the total number of nets used in a day work of each fisherman (12 hours in average). A first estimation of the fishing effort to the whole estuary was carried out using the fishing intensity data (nets/Km2/day) of a known area. Total catches in weight was composed, on average, by 66.7% of P. paulensis, 26.8% of the blue crab Callinectes spp, and 6.6% of fishes. The discards were mainly composed by juvenile fish of small size. Micropogonias furnieri (white croacker) and Netuma barba (marine catfish) were the dominant species in weight and number on discards and seem to be the most impacted species. Based on 15,866 nets estimated to the whole estuary during 1995 fishing season a total discard of 445.9 t was calculated, suggesting a substantial impact of this fishery on fish populations that use the estuarine environment as a nursery ground. The results seems to be more impressive when expressed as number of individual catched per season. Micropogonias furnieri showed general CPUE of 2.2 ind./net which result in 4.2 millions of individual catched per season. For N. barba, with a CPUE of 1.4 ind./net the total catch result on 2.7 millions of individuals per season. This work shows that the incidental catch of the Lagoa dos Patos shrimp fisheries is large and harmful to the white croacker and marine catfish fisheries. An effective control of the fishing effort the Lagoa dos Patos shrimp fisheries have to be done in order to avoid potential conflicts that this by-catch generates.

The Mundaú-Manguaba Lagunar-Estuarine Complex is located on the medium littoral in the State of Alagoas, Brazil. It is a multi-stressed ecocomplex secularly occupied by fishing communities and presently it suffers an increasing environmental degradation. A study was conducted (1985-1990) intending to detect the fishermen cognition, mainly in respect to the knowledge they have concerning with fish ecology. Their behavior as patch environment modifiers was also investigated. Some hipothesis were elaborated and one of them (related to the trophic ecology of the catfish Arius herzbergii was tested. Three cognitive aspects were specially investigated: ethnotaxonomy, space/time dimensions and trophic ecology. Three case studies were conducted: taxonomic/etfnotaxonomic aspects of the family Mugilidae (locally known as the "navel family"), patchy modification caused by the fishery gear/technology called as "caiçara" and the role of the trophic link between the mayflies locally known as "mariposas" and the catfish locally known as "bagre marruá" (A. herzbergii). Data were collected in interviews and questionnaires as well as by direct observations and tours conducted by fishermen. The classical taxonomic techniques (measurement and counts) and the usual stomach content analyses (numerical and occurence frequencies) were utilized to Mugilidae and Ariidae, respectively. Perceived ethnoecological models were obtained and they were compared to the ecological models in the scientific tradition. The concordance between one and another, although being not absolute, was impressive and this was strongly demonstrated in the case of the Ephemeroptera/Ariidae trophic link. The conclusions are: (a) the fishermen categorize the fish universe of their environment through multiple classificatory systems, including that based on taxonomic principles and ecological realities; (b) the correspondence between popular names/scientific names that scientific community proposes is questioned by the categorization they uo about the Mugilidae; (c) the fishermen share a sophisticated model concerning the spatial configuration and the temporal organization of their environment and behave in accordance with, such as by increasing local productivity; (d) the fishermen possess trophic models that include fish in a detailed and patterned manner which are coherent to the trophic models described in the pertinent literature; (e) one of these models (that related to the link ephemerids/catfishes), tested in laboratory, permits to consider Ephemeroptera being a circumstantially important item in the diet of Ariidae in tropical estuaries.

The river Subarnarekha, about 460 km in length, originates in the Chotanagpur plateau near Ranchi, traverses through
the states of Jharkhand, West Bengal and Orissa before meeting the Bay of Bengal about 1.5 km downstream of Kirtania
/ Chaumukha. Located in the state of Orissa, the entire estuarine stretch, about 50 km in length from Jaleswar to sea face,
constitutes around 10% of the total length of the river. Based on the primary observations on the salinity regime and
extent of tide, the Subarnarekha estuary was divided into three zones, viz., (i) Kirtania-Ramnagar (ii) upstream of
Ramnagar to Dahamunda and (iii) upstream of Dahamunda to Jaleswar. Information on the piscine fauna of the estuary
appears to be scanty. With this in view, a benchmark survey covering the period between April, 2008 and October, 2009
was conducted to evaluate the fish diversity of the Subarnarekha estuary. During the present course of investigations
140 species of fishes belonging to 18 orders and 55 families could be recorded of which estuarine / marine species
contributed around 59.29% (excluding species found both in estuarine and transitional zone) and those migrating
upstream even to freshwater zone. Perciformes constituted more than 45% of the total fish species recorded.

Ekosistem adalah hubungan timbal balik antara unsur biotik dan abiotik yang membentuk sistem ekologi. Ekosistem perairan dibagi menjadi tiga, yaitu perairan tawar, laut, dan estuari. Estuaria adalah wilayah pesisir semi tertutup yang mempunyai hubungan bebas dengan laut terbuka dan menerima masukan air tawar dari daratan. Tujuan praktikum ini adalah untuk mengidentifikasi kondisi perairan estuari melalui analisis parameter fisika, kimia, dan biologi. Metode yang digunakan dalam praktikum ini adalah metode sampling. Lokasi pengambilan data di Blanakan, Subang. Pengambilan sampel dilakukan sebanyak tiga kali pengulangan. Parameter fisika yang diamati adalah, kedalaman rata-rata sedalam 66cm, suhu perairan 28.3oC, warna perairan adalah hijau kehitaman, dan tipe substratnya lumpur. Nilai pH pada perairan sebesar 8.6 dan salinitas sebesar 5ppt yang merupakan parameter kimia. Parameter biologi yang diamati adalah plankton sebanyak 33 spesies, benthos sebanyak 1 spesies dan 3 spesies perifiton.

Mangrove vegetation is one of the forest ecosystems that offers a potential of substantial greenhouse gases (GHG) emission mitigation, due to its ability to sink the amount of CO2 in the atmosphere through the photosynthesis process. Mangroves have been providing multiple benefits either as the source of food, the habitat of wildlife, the coastline protectors as well as the CO2 absorber, higher than other forest types. To explore the role of mangrove vegetation in sequestering the carbon stock, the study on the use of remotely sensed data in estimating carbon stock was applied. This paper describes an examination of the use of remote sensing data particularly Landsatdata with the main objective to estimate carbon stock of mangrove vegetation in Perancak Estuary, Jembrana, Bali. The carbon stock was estimated by analyzing the relationship between NDVI, Above Ground Biomass (AGB) and Below Ground Biomass (BGB). The total carbon stock was obtained by multiplying the total biomass with the carbon organic value of 0.47. The study results show that the total accumulated biomass obtained from remote sensing data in Perancak Estuary in 2015 is about 47.20±25.03 ton ha-1 with total carbon stock of about 22.18±11.76 tonC ha-1and CO2 sequestration 81.41±43.18 tonC ha-1.

Keywords: Perancak Estuary, carbon stock estimation, mangrove, CO2 sequestration, NDVI

From a human history perspective, the intrinsic characteristics of estuaries have made them preferable sites of occupation and, consequently, intense areas of development. A direct consequence of human occupation of these coastal areas is that estuaries rank among the environments most affected by human presence and activities. The fast expansion of socio-economic activities on coastal and estuarine areas over the last decades, such as tourism, nature conservation, coastal fisheries and industrial and urban development has expanded and complicated the management tasks. In recent years, there has been a growing concern to maintain a steady growth in economical activities and social development in estuarine areas, while preserving their natural features and ecological services.

Given the acceptance by governments of the goal of sustainable development, a more sustainable coastal management strategy requires a more interdisciplinary and integrated management process. There are no easy answers to the question of what is best for a particular system from a resource’s management point of view. It is the task of scientists from different disciplines to present as complete a picture as possible to those who make decisions. The ECOMANAGE (Integrated Ecological Coastal Zone Management System) project described here, funded by the European Commission’s Sixth Framework Programme (Contract nº INCO-CT-2004-003715), aims to provide coastal authorities with the knowledge and tools for such an integrated management approach. The common goal was to work towards a social and environmental sustainable estuarine system management in three distinct transitional waters systems in South America: Santos Estuary in Brazil, Bahía Blanca Estuary in Argentina and Fjord Aysén in Chile. Besides their geographical location, these coastal systems cover a wide spectrum of management challenges because they vary significantly in their ecological state and human pressures, in a gradient that goes from a more pristine state of Fjord Aysén, to the heavily occupied and degraded system in Santos Estuary.

The South American continent is endowed with a unique and valuable marine heritage, which enclose several of the world’s largest and most productive estuaries. The accelerated development in most Latin American countries is posing demanding challenges in the management of natural resources, especially in coastal areas. Integrated coastal management approaches are required, combining all aspects of the human, physical and biological aspects of the coastal zone within a single management framework. Integrated coastal management is presented here as a broad, multi-purpose endeavor aimed at improving the quality of life of communities dependent on estuarine resources and helping local decision maker attaining sustainable development of estuarine areas, from the headwaters of coastal watersheds to the outer marine areas. The work presented in this volume is a step in that direction. Hopefully, the knowledge, experience, tools and results presented here will be used in other places with similar conflicting uses of natural resources.

Interdisciplinary and integration was the major thrust of ECOMANAGE. The project was originally assembled from scientifically promising and socially relevant research fields, with physical modelling and eutrophication as the core. The social sciences, human ecology and management oriented subjects were included to provide the project with the integrative principle. The work developed during the project formed the knowledge pool for this book. The volume is a collection of writings selected on the basis of novelty, relevance in a water resource management framework, and insightfulness. Contributions have also been included in order to survey the strengths and limitations of a range of existing coastal zone management practices operating in different local environmental and socio-economic contexts. The core message that is highlighted is that the management challenges posed are complex and multifaceted, encompassing physical forcing, natural hazard and variability and vulnerability, together with socio-cultural vulnerability problems.

Being the result of a multidisciplinary scientific endeavor, the book will have an audience that range across a wide spectrum of environmental and social disciplines. The book should be of interest for anyone working in the field of ICZM (Integrated Coastal Zone Management), from scientists to decision makers. Dealing with examples from South America, the book has a strong local interest. However, the kind of approach developed in the project and portrayed in the book enables this work to be used as a benchmark for scientists working worldwide in related areas or facing the same challenges.

The book addresses costal zone management in an integrative way, with particular focus on water resources. As such, we hope it will be of interest for scientists working in fields such as aquatic ecology, ecohydrology, ground water, marine sciences in general, water quality, coastal zone management, etc. In addition, the strong component of the modelling approach will target the modelling community, from ecosystem to ground water modelers.

Plankton plays an important role in a body of water as the primary producers and the beginning of the chain in the food web (food chain) causes the plankton used as a measure of fertility an ecosystem scale. This study aims to analyze the diversity and community structure of plankton in order to describe the condition of waters in the estuary Perancak, Bali.. This research was conducted by field surveys in September 2015 (transitional season II), consisting of three location , namely data collection Loloan River (north), Dermaga Perancak (middle) and Muara Perancak (south). Based on the results, both plankton abundance of phytoplankton and zooplankton ranged between 300-20100 ind/m3 and 300-28500 ind/m3. An abundance of plankton in the Estuary Perancak influenced by the water quality, especially the concentration of nutrients (phosphate, silicate and nitrate). Ecological index showed that species diversity of phytoplankton in the Estuary Perancak was categorized as low diversity (0,98≤H'≤ 1.38) and no species of phytoplankton dominating (0,55≤E≤0,77) with uniformity kind of approaching a stable and tend evenly (0,32≤ D≤0,48). While the index showed that diverisity index of zooplankton is low (1,06≤H'≤1,29), with the distribution species are fairly uniform and relatively similar (0,54≤E≤1), and dominant species is not present (0,33≤D≤0,51). These results indicate that Perancak Estuary is moderate levels of water pollution. It is known from the low diversity index of phytoplankton and zooplankton in the waters of  Perancak Estuary.
Keywords: plankton community structure, Perancak Estuary, abundance, diversity, dominance index.

Pada saat muson tenggara perairan selatan Jawa, Bali dan Nusa Tenggara mengalami upwelling yang berpengaruh ke perairan selat Bali disebut sebagai in-direct upwelling. Pengaruh upwelling ini bisa dilihat dari perubahan parameter fisika, kimia dan biologi perairan seperti suhu, klorofil-a dan nutrien. Penelitian ini bertujuan untuk mengetahui pengaruh terjadinya upwelling terhadap distribusi suhu, klorofil-a dan nutrien terutama nitrat,
fosfat, dan silika di Selat Bali dari hasil observasi bulan Juni-September 2012. Lokasi penelitian di koordinat 8,4 LS – 8,85 LS dan 114,40 BT – 115,5 BT. Metode yang digunakan adalah observasi lapangan saat terjadinya upwelling. Pengukuran parameter suhu dan klorofil-a menggunakan Conductivity Temperature Depth (CTD). Sampel nutrien
diambil tiap layer kedalaman dari permukaan sampai 100 m dibagi menjadi 3 zona mewakili karaketristik perairan utara (Laut Bali), tengah (Selat Bali) dan selatan (Samudera Hindia). Hasil penelitian menunjukkan terjadi peningkatan konsentrasi nutrien yang terlihat dari peningkatan konsentrasi nitrat, fosfat, silikat dan klorofil-a serta penurunan suhu. Konsentrasi klorofil-a maksimum di kedalaman 20 m zona selatan yang berhubungan langsung dengan Samudera Hindia dan terjadi kenaikan massa air dingin dikedalaman 70 m serta peningkatan konsentrasi fosfat di kedalaman 60 m, hal ini memperkuat bahwa pada bulan Juni-September perairan selat Bali mendapatkan pengaruh upwelling kuat dari Samudera Hindia.
Kata kunci : in-direct upwelling, suhu, klorofil-a, nutrien

The wide spatial distribution of wetlands (e.g., swamps, bogs, marshes, and mires) across different latitudes and geomorphological settings reflects their complex biotic and abiotic interactions that define their ecological function and high economic value. As space becomes more limited, and landscape fragmentation increases, competition over land area for development and related human activities will certainly limit management options/decisions related to the conservation and rehabilitation/restoration of wetland ecosystems, especially at large spatial scales. In this chapter, we draw information from multiple sources and experiences to compile a series of case studies to focus our attention on characterizing the direct and indirect causes of wetland degradation and loss, particularly in coastal regions. The examples used in this chapter include deltaic regions (Mississippi River Delta, Louisiana, USA; Grijalva–Mezcalapa–Usumacinta, Mexico; and Central Coast, Netherlands), islands (Puerto Rico), and karstic platforms (Everglades, FL, USA). Current estimates of global wetland área range from 6.8 to 10.1 million km2, which represents 5–8% of the Earth (56% in tropical and subtropical regions). Loss of approximately 50% of wetlands around the world indicates the significant effect of human activities. Practices such as excessive harvesting, hydrological modifications and seawall constructions, coastal development, and pollution are some of the most pressing causes of wetland loss. Similarly, inland wetlands have been impacted by constant hydrologic modification and agriculture and urban development. The examples presented in this chapter underline the dynamic interaction between human actions and wetland habitat reduction at local and global scales. These issues define well the scope of ‘human use and abuses’ of productive ecosystems vital for the sustainability of both poor and rich nations. However, present political, social, and economic structures in most of the coastal regions around the world are disconnected from the actual functioning of the natural environment in which they reside, hindering conservation of productive wetland ecosystems.

The Patos Lagoon estuary (PLE; BR-LTER Site 8; approx. 1,000 km2), located in the extreme south of the Patos Lagoon (32 ° 00 ‘S, 52 ° 05’ W) has a high biological productivity, ecological complexity, and great economic importance due to harbor and industrial activities in the region. In this chapter we present a synthesis about the hydrological and biological variability in the PLE and its relation with the natural and anthropogenic impacts based on the data obtaind continuosly and sistematically for more than ten years.

Pada buku ini, akan dikupas hasil-hasil penelitian terkait dengan
model (kasus) pengelolaan ekosistem perisir dan lautan yang ada di
Indonesia. Studi kasus dari masing-masing bagian mengkaji tentang
kawasan estuari, kawasan ekosistem mangrove, kawasan ekosistem
lamun, kawasan ekosistem terumbu karang, pengelolaan ekowisata
pantai, dan kawasan pulau-pulau kecil, di Indonesia yang melibatkan
masyarakat dan pemerintah. Diharapkan buku ini dapat menjadi
salah satu alternatif pengelolaan ekosistem perairan tropis yang ada
di Indonesia
Dalam penyusunan buku ini, tim penulis banyak dibantu oleh
berbagai pihak, baik secara moril maupun materiil, maka izinkan
penulis mengucapkan terima kasih kepada berbagai pihak yang telah
membantu dalam menyusun dan menyelesaikan tulisan ini. Semoga
tulisan ini dapat bermanfaat bagi penulis khususnya dan pembaca
pada umumnya

Natural or anthropogenic induced variations in estuaries and the dynamics of marine fish populations potentially promote differences in connectivity between estuaries and marine areas, i.e. in their importance as nursery grounds. Within this context, an integrated assessment of the differential nursery function of the main estuaries along the Portuguese coast for commercial fish species common sole Solea solea, Senegalese sole Solea senegalensis, flounder Platichthys flesus and sea bass Dicentrarchus labrax was performed through several indicators based on available data. Contribution of individual estuaries to marine subpopulations was measured with potential metrics (juvenile density, habitat quantity, juvenile number and habitat quality within estuaries) and effective metrics (estuarine source of young adults in marine environment measured via otolith elemental fingerprints). The relationship between the two types of metrics was also assessed. Estuaries identified as important nursery and/or effective juvenile habitat (EJH) differed with species and no single estuary was best for all, highlighting species-specific regulation of nursery function. Multiple species assessment of nursery and EJH function differed among estuaries. Management and conservation of estuaries should focus on sites with higher contributions to adult subpopulations of multiple species. The importance of defining precise scientific and management objectives was emphasized by the different rankings of estuaries obtained with nursery or EJH criteria. Potential and effective contribution of estuaries were not significantly correlated, but in a quantitative analysis juvenile densities and number of juveniles seem related with effective contribution in some species. An agreement between potential and effective contributions of estuaries is concurrent with the acknowledged minor role of juvenile stage processes in regulation of recruitment to adult subpopulations.

Perairan Muara Gembong merupakan salah kawasan dengan fungsi ekologis sebagai daerah asuhan dan pemasok sumber daya perikanan yang tinggi di Teluk Jakarta (Puspasari et al., 2017). Hal ini dikarenakan perairan Muara Gembong dan sekitarnya masih memiliki hutan mangrove yang cenderung tinggi dibandingkan dengan muara-muara lainnya di Teluk Jakarta (Suwargana, 2008). Perairan Muara Gembong menghadapi berbagai masalah dari Sungai Citarum yang menjadi sungai utama yang bermuara di Muara Gembong berupa pencemaran (Sachoemar & Wahjono, 2007; Permanawati et al., 2013) dan sedimentasi (Paryono et al., 2017) yang memberi tekanan ekologis pada ekosistem estuaria hingga abrasi (Putra, 2016) dan kerusakan mangrove (Suwargana, 2008) yang memberi tekanan ekologis pada ekosistem pesisir.
Sumber daya ikan yang tertangkap dan teridentifikasi di perairan
Muara Gembong terdiri atas 52 famili, 84 genera, dan 103 spesies. Jenis
ikan laut-estuaria merupakan kelompok kategori bioekologis yang banyak ditemukan, yang mengindikasikan bahwa perairan Muara Gembong merupakan daerah asuhan. Komunitas ikan di perairan Muara Gembong masih tergolong baik dengan kategori moderat secara ekologi. Daerah perlindungan dengan pengelolaan konservasi di perairan estuaria Muara Gembong diperlukan untuk menjaga keanekaragaman dan kelimpahan jenis-jenis ikan laut-estuaria untuk menyokong perairan Teluk Jakarta.

Spatio-temporal distribution and composition of ichthyoplankton assemblages were studied in the Golden Horn estuary (Istanbul) over a 10-month period. Environmental parameters were considered to determine the environmental status in different parts (upper, middle and lower) of the estuary. The ichthyoplankton composition of the Golden Horn estuary consisted of 23 species and was dominated by Mullus sp., Diplodus spp. and Liza sp. The largest densities of fish eggs and larvae were found in September 2009 with 786.4 ind. 100 m–3 and 355.9 ind. 100 m−3, respectively. As supported by the multivariate analysis, most species showed a seasonal pattern, with the presence of higher densities during summer and winter. Moreover, the spatial pattern showed that ichthyoplankton distribution and diversity was relatively high in the lower part of the Golden Horn and gradually decreased through the upper parts. Canonical correspondence analysis revealed that spatial changes in depth and water clarity were the main factors forcing larval assemblage distribution and leading to a decrease in density and diversity of fish larvae through the upper part of the estuary. For the seasonal changes, sea surface salinity and chlorophyll a were the main factors in shaping the structure of the larval assemblage and increasing sea surface temperature lead to an increase in the density and diversity of fish larvae.

O estudo da composição do fitoplâncton torna-se essencial quando se percebe a importância e
influência deste na dinâmica da vida aquática. Conhecer os seus componentes, sua frequência e a
relação com os processos físico-químicos ocorrentes no meio traduz-se no conhecimento da
biodiversidade e do sistema ecológico que ali se desenvolve. Desta forma, este ensaio busca
demonstrar o estado da arte das pesquisas fitoplanctônica no Brasil, bem como o desenvolvimento
destas na região Amazônica e no Estado do Amapá. Observa-se que os estudos sobre fitoplâncton
no Brasil vêm crescendo com o decorrer do tempo, principalmente, em função da formação de novos
profissionais na área. Entretanto na Amazônia tais estudos ainda apresentam-se de forma
insuficiente. No estado do Amapá, estudos ficológicos (pesquisas sobre fitoplâncton) ainda são
pouco desenvolvidos. A geração de dados e informações acerca de sua biodiversidade é primordial
para sua conservação e preservação, como também para subsidiar o desenvolvimento de pesquisas
aplicadas na área.

In northwest Europe conflicts have routinely occurred between economic and conservation interests regarding shellfish such as cockles and mussels. The harvest of these species is economically important, but shellfish also constitute the main overwinter food supply of the oystercatcher Haematopus ostralegus. In this report we describe attempts to produced a simplified modelling approach to predict the quantities of shellfish which need to be left unharvested in order to ensure high overwinter survival of oystercatcher.
We review oystercatcher diet and prey selection in order to quantify the dependence of this species on shellfish, and determine the size ranges of shellfish which the birds consume. We also review the food requirements of oystercatchers, based on their energetic needs and the nutritional quality of shellfish. In general the data agree well with those used in previous oystercatcher modelling studies. However, there is a possibility that the daily energy requirements, calculated from an all bird allometric equation, may yield an underestimate of oystercatcher food requirements. A comparison of the physiological food requirements, i.e. the quantity directly consumed, and the ecological food requirements, i.e. the quantity required to avoid high mortality, indicated that the ecological food requirement was between 2.0 and 7.8 times greater, with the value depending on the proportion of cockles Cerastoderma edule and mussels Mytilus edulis in a site.  These ratios are calculated from empirical data on oystercatcher survival and the predictions of individual-based models predicting the relationship between mortality rate and the abundance of the food supply. Data from the Burry Inlet indicated that the mean ecological food requirement was 3.3 times greater at this site.
We describe a simplified spreadsheet model, which we used to predict the food requirements of the oystercatcher population of the Burry Inlet, and thus the quantity of shellfish which must be left unharvested in order to maintain low mortality rate. The model is based on parameter values derived from the literature reviews in this study, including the energy requirements of the birds, the energy content of shellfish, the minimum size of cockles and mussels consumed, and the ratio of the ecological and physiological requirements. We describe the assumptions and limitations of the model, and compare the model with more detailed individual-based models that can be used to predict the mortality rate of shorebirds in relation to the amount of food available.

The waters of the Bay of Bengal intrude into the Sunderbans over flooding the creeks and dal courses for years as a result of sea level rise due to climac changes. This situaon causes ecological disaster for the man and environment. Erosion and inundaon, as a result of sea level changes removes sediments from the flood plain and river banks by the current and wave accons. Islands of Sunderbans face inundaon that somemes results flood in the agricultural lands and gradually become a low lying land because of submergence. Hazards as a result of climac changes affect the geographical locaon, structure and funccon of biooc community, livelihood of the rural islanders of Sunderbans. Further, changes of ecosystem of the Sunderbans have the major impact on the tourism, fisheries, biodiversity, fresh water supplies, and ground water availability due to intrusion of salinity. Sea-level Rise Connuous subsidence of the Bengal basin results much more sea level rise than that of eustac rates of 2.2 mm/year. Global climac change causes the sea-level rise, although the sea-level rise girdling the coastal areas of the Sunderbans is alarming. Current trend of sea-level rise along the Indian Ocean is 2.5 mm/year against the long-term sea-level rising trend of 1.0 mm/year. IPCC (Intergovermental Panel on Climate Change) predicts their expectaon on sea-level rise of about 15-38 cm by 2050 and 46-59 cm by 2100 around Indian subconnent. World Bank Report (2000) projected the sea-level rise for the Sunderbans step by step by menoning the percentage of inundaon for the Sunderbans which is published by Lund University, Sweden (2000). Projected height of the sea level rise and percentage of inundaon of the Sunderbans Sea-level rise (in cm) Inundaon (%) 10 cm 25 cm 45 cm 60 cm 15 40 75 100 Bangladesh faces about the double of the sea-level rise of 30-50 cm by 2050, on contrary to the 15-38 cm of the global average. Much greater sea-level rise of about 1 m for the Bangladesh Sunderbans coincides with the local sea-level rise of 10 cm due to subsidence with the 90 cm sea-level rise for global warming due to climac change. About 20 islands of both Bangladesh and Indian Sunderbans including emerging New Moore Island (Purbasha) are to be undergone submergence. Subsidence It was not a tale of a tub when everybody who was anybody at all was at the gathering of experiences of finding in-depth tree-trunks in the Sunderbans in the past century. The local inhabitants at present are going out of their depth observing these sediment-sunk tree trunks over the centuries. Series of tree trunks are seen scaered in the most of the excavated ponds in the depth of eight to eighteen feet in the blocks of Canning, Patharprama, Gosaba, Mathurapur, Namkhana etc. of the Sunderbans region. And they are all idenfied as the tree trunks of the Sundari trees. The similar incident of the occurrence of tree trunks at the depth of 30 feet below the surface level was experienced during excavaon at Khulna and Sealdah in the Briish period. The then Director of the Botanical Gardens confirmed idenfying those in situ tree trunks as Sundari trees. Experts describe both of these incidents of past and present as the evidences of subsidence. Evidence of subsidence is the existence of Sundari trees at a much lower level (3 to 6 m) than the present surface near Calcuua (presently Kolkata) and Khulna proves that the old forest areas must have subsided to that depth where tree trunks are available. Burial of earlier mangroves layers by subsequent alluvial deposits is a common and rouune phenomenon in the Sunderbans. Further, llng of landmass eastward as a result of a crack developed in the connental shelf of the Bengal basin during the Cretaceous period has created a shallow marine condiion at the southern boundary of the Sunderbans and the mangroves tend to shii northwards due to natural pressure. Shiiing of mangroves about 130 km north was happened to be occurred around 6500 BP as a result of transgression. Sunken tree trunk of mangroves found in the Sealdah and Khulna during excavaon is the evidences for both subsidence and shiiing of mangroves from the south to the north. The reality of the facts of subsidence phenomenally is correct with respect to the geology of the Bengal Basin. The Sunderbans occupies the lower (dal) delta plain of the Ganges-Brahmaputra Delta (GBD) of the Bengal Basin which is slowly subsiding as a result of isostac adjustment of the crust due to rise of the Himalayas and dewatering of the Proto-Bengal Fan sediments. Further, in the Sunderbans,

Wide estuaries are natural magnets for urban development. Several of the World’s major cities developed around estuaries, but at the same time encroached upon some of the most complex and vital ecosystems. Sea-level rise threatens to submerge both rare wetland habitat and essential urban areas and infrastructure. This prospect discloses the urgency of balancing urban development and environmental protection in Metropolitan Estuaries. The hard task of dealing with this threat may provide the opportunity to promote an integrated approach to regional planning, where the necessary adaptation of cities to sea-level rise could equally promote the preservation, or even the enhancement, of wetland habitat. The two case study metropolitan estuaries, San Francisco Bay (California, USA) and the Tagus Estuary (Lisbon, Portugal), share striking similarities in terms of morphology. They both host large metropolitan areas and important wetland ecosystems. Nevertheless, a finer analysis of development patterns reveals crucial differences in the extent of shoreline alteration and types of land use that now encroach upon natural estuarine habitat. The comparative study of both estuaries provides mutually beneficial insights on the shortcomings of each system, and helps identify opportunities to enhance coastal zone management, adaptive governance and environmental planning efforts. The evolution of both estuaries throughout the Holocene is reconstructed, with special emphasis on the process of anthropogenic alteration. While this impact has been significant and continuous in the Tagus Estuary for over two millennia, large scale disturbance of the San Francisco Bay was concentrated in the last two centuries. The legal frameworks that have guided, with varying degrees of effectiveness, the process of wetland reclamation and landfilling share a common ancestry in the Roman Law. These have evolved continuously in Lisbon and the State has upheld with relative success the provision to keep estuarine lowlands in public control, even as they were steadily transformed to farmland. In San Francisco, a period of deep disturbances over the Sacramento River’s hydrology was coupled with extremely fast and under regulated development of lowlands. During a short period, the property of these lands, which would theoretically fall within the Public Trust, was transferred to local governments and private landowners, which led to their steady transformation onto salt ponds, industrial zones and even residential neighborhoods. As a consequence, the Bay Area now has extensive developed areas at very low elevations, vulnerable to low levels of sea-level rise, and remaining wetlands are now heavily encroached upon by urban development. Around the Tagus Estuary, while most original wetlands have long been drained for farmland, the remaining patches are adjacent to non-urban land uses, which could facilitate future efforts of restoration or allow wetland migration with rising seas. A comparative modelling of sea-level rise flooding over existing land uses reveals that, while around the Tagus Estuary most reclaimed lowlands are reserved for farmland and urban development over landfill is limited, the extent of developed urban areas at very low elevations is much greater around the SF Bay, which renders the region more vulnerable to early stages of SLR. Nonetheless, both cities have begun to incorporate climate adaptation onto their main environmental planning blueprints, for which they can be seen as early adopters of local sea-level rise adaptation strategies. Through interviews with stakeholders and document analysis, the planning and decision-making exercises that led to the recent elaboration of the first Tagus Estuary Management Plan, and the Bay Plan Climate Change Amendment, are analyzed and discussed. Lisbon benefits from a very simple, top-down, planning structure, with a handful of public entities directly communicating and articulating stakes and approaches along the planning process. A lack of transparency as to some specific interventions and a still somewhat incipient tradition of public participation have contributed to protract the Plan’s final approval. The Bay Area institutional framework is well-used to collaborative planning efforts, which are usually successful in articulating conflicting interests, but are prone to limitations derived from narrow, and often difficult to expand, mandates for environmental planning agencies, within an extremely complex, multi-level, governance structure involving three levels of government and very active interest groups. While broad mitigation/adaptation strategies are decided at the National or State levels, the actual implementation of SLR adaptation measures often require a great deal of involvement of local actors. Given that it is at this juncture that adaptation takes a concrete spatial expression, this is also the moment when land-use conflicts arise. Local governments are left with much of the burden of mediating competing interests, between urban development, environmental protection, and other social demands. In some instances, the prospect of shoreline development may be very attractive for both property owners/developers and local governments, given the potential land value and economic benefits, but these have to be weighed against the medium-/long-term costs of defending these assets from rising sea-levels. In San Francisco Bay, there is an increasing awareness of the challenges posed by SLR, but the institutional arrangements are complex, and communication between the different public agencies/departments is not always as streamlined as it could be. Some agencies and departments need to adapt their procedures in order to remove institutional barriers to adaptation, but path dependence is an obstacle. The several projects where different federal and state agencies are partnered with local governments highlight the benefits of a more frank and regular communication between public actors. It also emphasizes the benefits of a coordination of efforts and strategies, something that was eroded in the transition from government-led policies to a new paradigm of local-based adaptive governance. Whereas the articulation of public actors is often easy to address by increasing communication and coordination, conflicts involving private landowners and developers may be much complicated by the threat of litigation. The lack of a strong legal backing to public environmental protection mandates is a major obstacle to shoreline planning around the Bay and elsewhere, and this is highlighted by the extreme caution of some public agencies in upholding their jurisdictions over private property. Environmental NGOs have, in the case of California, a big role to play, as they are able to resort to the same legal and lobbying instruments as the developers, and may help even-out the field between public stakeholders with limited legal and economic resources, and powerful private developers with nothing to lose. There is seemingly a sense of urgency in pushing for the development of shoreline properties, as public opposition to development on locations exposed to SLR is most likely to increase in the coming decades. At the same time, NGOs and public agencies are aware of the stress wetlands will be under as the rates of SLR increase towards the end of the century. “Green”, or ecosystem-based, adaptation is already on the way around the Bay. Large scale wetland restoration projects have already been concluded, and further action now often requires articulation with the reinforcement of flood defense structures, given the level of urban encroachment. While levee setback, or removal, would provide greater environmental benefit, the need to protect urban areas and infrastructure has led to the trial of ingenious solutions for promoting wetland resilience while upgrading the level of protection granted by levees.

There is growing concern over observed declines in fish catch and therefore
catch rate in coastal water bodies in Ghana which have been attributed, in part,
to changes in the environment and excessive pressure on exploited fish
populations. This research examined biological performance measures
(abundance and growth) of estuarine fish under varying physico–chemical
factors such as temperature, salinity, dissolved oxygen and pH. Experimental
fishing with seine net was done while specified water quality parameters were
also collected simultaneously on a monthly basis for eight months in three
identified salinity zones of the Volta estuary. The results indicated that
temperature and salinity caused most variation in fish abundance. There were
a total of 2,333 individual fishes caught in the survey. Most species examined
were juveniles of marine migrants; these species ranged from 2.5 to 10 cm.
This reinforces the fact that the estuarine environment serves as breeding and
nursery ground for a number of fishes. The dominant fish species by number
encountered were Caranx hippos, Mugil cephalus and Ethmalosa fimbriata.
Fish growth was estimated using length-weight relationships and condition
factor. The von Bertalanffy growth function determined for the dominant
fishes indicated slow growth. Precautionary management measures should be
implemented to regulate their exploitation to help sustain fish populations in
the estuary and the adjacent freshwater and marine environments.

Crabs are amongst the most conspicuous and ecologically important organisms inhabiting nearshore environments. Their complex life cycle and bioindicator capacity makes them good models for the study of distribution and abundance patterns of marine fish and benthic invertebrate populations. Such knowledge is essential for explaining species occurrence and demographic patterns, predicting the success of biological indicators and controls, as well as for conservation and management purposes of exploited populations and ecosystems. In this study, the impacts of specific environmental constraints at different life phases of estuarine and coastal crabs on population structure and physiological condition were evaluated and related to habitat quality. During settlement and recruitment events, the patchiness of artificial substrates significantly influenced settlement estimation, and strong water currents might have resulted in a decoupling pattern between supply and settlement. Estuarine sandy habitats presented higher quality for early recruits than seagrass ones. In fact, vegetated habitats were not of higher quality for crab populations than non-vegetated and rocky-shore ones. Adult-juvenile cannibalism showed potential to structure intertidal crab assemblages, especially under shortage of food and refuge. Interestingly, mangrove crabs were more affected by climatic season than by pollution, and coped well with several combinations of vegetation and sewage load. Specific constraints of different life stages, individually and in combination, must be considered for full understanding distribution and abundance patterns of crab populations. Furthermore, the relative importance of a specific constraint is likely to change throughout ontogenesis, and the mechanisms by which it interacts with other environmental variables and processes, sometimes synergistically, have also to be considered. This study constitutes an extension to the knowledge on population structure and physiological condition of coastal and estuarine crabs and other marine invertebrate and fish species, and on their use as indicators of ecological status of habitats and ecosystems.