Abstract A resident wild dolphin is reported to avoid the discharge plume from the Red River whic... more Abstract A resident wild dolphin is reported to avoid the discharge plume from the Red River which empties into the northern end of St Ives Bay. The river effluent is found to contain a high load of finely divided metalliferous particles rich in iron but also containing significant amounts of Sn, As, Cu and Zn. It is suggested that the echo-location system and/or chemosensory system of the dolphin may be affected by this discharge causing the animal to avoid the area of the effluent.
Three male sperm whales (Physeter macrocephalus) stranded on the island of Andøya in northern Nor... more Three male sperm whales (Physeter macrocephalus) stranded on the island of Andøya in northern Norway in 2020. This created an opportunity to do gross necropsies with a focus on stomach contents as the diet of sperm whales in Norwegian waters is poorly understood and also to study potential presence of marine debris. Four new prey types for sperm whales in Norwegian waters were identified: (1) angler fish, (2) Atlantic cod, (3) cartilaginous fish, and (4) cock-eyed squid. In general, the results support earlier studies of male sperm whale diet in high latitude foraging grounds in the North Atlantic consisting of a mixture of cephalopods and meso- and bathypelagic fish. The only type of marine debris found was part of a fishing line. Based on estimates from teeth, the whales were 25, 45, and 49 years old. The size of all individuals was smaller than the median length based on whaling data for these age classes caught in Iceland in the 1970s.
Tooth ultrastructure in harbour porpoise is examined as a possible tool for differentiating betwe... more Tooth ultrastructure in harbour porpoise is examined as a possible tool for differentiating between animals from different geographical regions in the North Atlantic. Nine different characteristics in both dentine and cementum are identified and recorded in the decalcified, sectioned and stained teeth. Significant differences in several characters are found between porpoise tooth samples from the Canadian east coast and West Greenland, between Iceland, the North Sea, and Celtic Shelf, as well as sub-divisions within the North Sea, and between the North Sea, Skagerrak, Kattegat, Inner Danish waters and the Baltic Sea. The method appears promising if used on groups of known geographic origin. However, it is not certain that any one tooth could be assigned to a particular geographic group, when selected randomly.
Abstract A resident wild dolphin is reported to avoid the discharge plume from the Red River whic... more Abstract A resident wild dolphin is reported to avoid the discharge plume from the Red River which empties into the northern end of St Ives Bay. The river effluent is found to contain a high load of finely divided metalliferous particles rich in iron but also containing significant amounts of Sn, As, Cu and Zn. It is suggested that the echo-location system and/or chemosensory system of the dolphin may be affected by this discharge causing the animal to avoid the area of the effluent.
Three male sperm whales (Physeter macrocephalus) stranded on the island of Andøya in northern Nor... more Three male sperm whales (Physeter macrocephalus) stranded on the island of Andøya in northern Norway in 2020. This created an opportunity to do gross necropsies with a focus on stomach contents as the diet of sperm whales in Norwegian waters is poorly understood and also to study potential presence of marine debris. Four new prey types for sperm whales in Norwegian waters were identified: (1) angler fish, (2) Atlantic cod, (3) cartilaginous fish, and (4) cock-eyed squid. In general, the results support earlier studies of male sperm whale diet in high latitude foraging grounds in the North Atlantic consisting of a mixture of cephalopods and meso- and bathypelagic fish. The only type of marine debris found was part of a fishing line. Based on estimates from teeth, the whales were 25, 45, and 49 years old. The size of all individuals was smaller than the median length based on whaling data for these age classes caught in Iceland in the 1970s.
Tooth ultrastructure in harbour porpoise is examined as a possible tool for differentiating betwe... more Tooth ultrastructure in harbour porpoise is examined as a possible tool for differentiating between animals from different geographical regions in the North Atlantic. Nine different characteristics in both dentine and cementum are identified and recorded in the decalcified, sectioned and stained teeth. Significant differences in several characters are found between porpoise tooth samples from the Canadian east coast and West Greenland, between Iceland, the North Sea, and Celtic Shelf, as well as sub-divisions within the North Sea, and between the North Sea, Skagerrak, Kattegat, Inner Danish waters and the Baltic Sea. The method appears promising if used on groups of known geographic origin. However, it is not certain that any one tooth could be assigned to a particular geographic group, when selected randomly.
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Papers by Christina Lockyer