Oceanographic and demographic mechanisms affecting population structure of snow crabs in the northern Bering Sea

Marine Ecology Progress Series

Markus A. Janout¹  James R. Lovvorn¹  Jason M. Kolts¹  Christopher A. North¹ 

关键词: Population structure;    Larval advection;    Larval settlement;    Ontogenetic migration;    Dispersion;    Reproduction;    Chionoecetes opilio;   

DOI  :  10.3354/meps11042

学科分类：海洋学与技术

来源: Inter-Research

【 摘 要 】

ABSTRACT: Snow crabs Chionoecetes opilio are quite productive at suitable temperatures, but can also be abundant in water cold enough to depress settlement of larvae, growth, and reproduction. In much of the northern Bering Sea, bottom water temperatures are below -1°C for most or all of the year. Crab pelagic larvae prefer to settle at temperatures above 0°C, so we found high densities of juveniles only where intruding warm currents deposited larvae in localized areas. After settlement, maturing crabs appeared to exhibit ontogenetic migration toward deeper, warmer water. Cold temperatures excluded key predators, but decreased fecundity by restricting females to small body size (with associated small clutches) and to breeding every 2 yr. Migration to warmer water may allow females to breed annually and to encounter more adult males needed to fertilize subsequent clutches. Because older males also emigrate, remaining adolescent males probably inseminate newly maturing females. Without localized intrusion of warmer currents, snow crabs might not persist at high densities in such cold waters. However, they are currently very abundant, and export many pelagic larvae and adults.

【 授权许可】

Unknown