scholarly journals Collapse and recovery of forage fish populations prior to commercial exploitation

2017 ◽  
Vol 44 (4) ◽  
pp. 1877-1885 ◽  
Author(s):  
S. McClatchie ◽  
I. L. Hendy ◽  
A. R. Thompson ◽  
W. Watson



2014 ◽  
Vol 71 (9) ◽  
pp. 1349-1362 ◽  
Author(s):  
David E. Richardson ◽  
Michael C. Palmer ◽  
Brian E. Smith

Shifts in the distribution and aggregation patterns of exploited fish populations can affect the behavior and success of fishermen and can complicate the interpretation of fisheries-dependent data. Starting in 2006, coinciding with an increase in sand lance (Ammodytes spp.) abundance, Gulf of Maine Atlantic cod (Gadus morhua) concentrated on Stellwagen Bank, a small (405 km2) underwater plateau located in the southwestern portion of the larger (52 461 km2) stock area. The cod fishery in turn concentrated on Stellwagen Bank. Specifically, the proportion of Gulf of Maine cod landings caught in a single 10-minute square area (260 km2) encompassing the tip of Stellwagen Bank increased from 12% in 2005 to 45% in 2010. An increase in landings per unit effort in the fishery coincided with the concentration of the fleet on Stellwagen Bank. Overall, both fisheries-independent and fisheries-dependent data indicate that an increase in sand lance abundance resulted in cod aggregating in a small and predictable area where they were easily caught by the fishery. More broadly, this work illustrates how changes in the distribution patterns of fish and fisherman can decouple trends in abundance and fisheries catch per unit effort.



1987 ◽  
Vol 44 (3) ◽  
pp. 515-524 ◽  
Author(s):  
Thomas F. Nalepa

A benthic survey of 40 stations in southern Lake Michigan in 1980–81 was compared with results of studies conducted in the mid-1960's to evaluate long-term trends in populations. The three major benthic groups, Pontoporeia, oligochaetes, and sphaeriids, were significantly more abundant in 1980–81. Compared with the most comprehensive survey (conducted in 1964–67), Pontoporeia increased two- to fivefold at depths less than 50 m, but did not increase at depths greater than 50 m. Oligochaetes increased two- to threefold regardless of sampling depth, while sphaeriids increased twofold at depths less than 50 m but decreased somewhat at depths greater than 50 m. Although oligochaete abundances increased, overall shifts in species composition were not apparent. Changes in abundances of Pontoporeia may have been related to shifts in predation pressure from forage fish populations, but increased oligochaete abundances can likely be related to increased enrichment between the two sampling periods. Although apparent improvements in the water quality of Lake Michigan since the mid-1970's were not yet reflected by benthic populations in 1980–81, continued monitoring of the benthos should provide a useful indicator of future trends.





2020 ◽  
Vol 226 ◽  
pp. 105520
Author(s):  
Katelynn M. Lankowicz ◽  
Hongsheng Bi ◽  
Dong Liang ◽  
Chunlei Fan


2015 ◽  
Vol 2 ◽  
Author(s):  
Cardoso Gabriela ◽  
Quintella Bernardo ◽  
Mateus Catarina ◽  
Alexandre Carlos ◽  
Belo Ana ◽  
...  


2011 ◽  
Vol 91 (4) ◽  
pp. 360-381 ◽  
Author(s):  
Michael Ballón ◽  
Arnaud Bertrand ◽  
Anne Lebourges-Dhaussy ◽  
Mariano Gutiérrez ◽  
Patricia Ayón ◽  
...  






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