Seasonal and daily variation in distribution and abundance of some shallow water benthic marine fish species of Logy Bay, Newfoundland, with special reference to Myoxocephalus scorpius and M. octodecemspinosus

• Main Author: Pepper, V. A. (Vernon A.)
• Format: Thesis
• Language: English
• Published: Memorial University of Newfoundland 1974
• Subjects: Gulch; Small Rock; Newfoundland
• Online Access: https://research.library.mun.ca/7308/; https://research.library.mun.ca/7308/1/Pepper_VernonA.pdf; https://research.library.mun.ca/7308/3/Pepper_VernonA.pdf

Investigation of the seasonal and daily movements of some shallow water benthic marine species in a small, rock bounded "gulch" of variable depth in Logy Bay, Newfoundland, revealed that two species of sculpin, Myoxocephalus scorpius and M. octodecemspinosus were the most common fish inhabitants of the area. M. octodecemspinosus dominated the area's fish fauna during the summer months. Although M. scorpius was a year round inhabitant of the area, its population was greatly decreased in the winter. Analyses of distribution patterns for these two species indicated that M. octodecemspinosus ranged through the depth gradient of the gulch and occupied various types of open bottom terrain. M. scorpius was more common in the lower reaches of the gulch and was associated with cover throughout the summer months. This cryptic behaviour subsided during the winter months subsequent to the fall emigration of M. octodecemspinosus from the area. -- Stepwise multiple regression and correlation analyses of the numbers of M. scorpius, M. octodecemspinosus and Stichaeus punctatus per unit area suggested that, of the physical and biological parameters examined, photoperiod, temperature and the degree of water movement were correlated with the abundance of these benthic fish species in the study area. Linear prediction models of abundance of M. scorpius, M. octodecemspinosus and S. punctatus per unit area are presented. Deficiencies of these models are discussed. -- Observations of M. scorpius and M. octodecemspinosus at night suggest interspecific avoidance by reciprocal movements into and out of the study area at dawn and dusk. The numbers of M. scorpius present in the study area decreased at dusk and increased again at dawn. -- Pseudopleuronectes americanus was abundant in the area from late May to September. A dense aggregation of P. americanus observed after dark in late June is described. -- Times of immigration and emigration of Limanda ferruginea were similar to those of P. americanus.