Sanchez-Rubio et al. : Climate-related hydrological regimes and their effects on abundance of juvenile Ca/linectes sapidus 
145 
less of the level of recruitment, by the time crabs reach 
~30 mm CW, population abundance begins to level off 
and then decreases at a gradual rate. In that study, 
high numbers of megalopae and early-stage crabs did 
not result in proportionally elevated numbers of late- 
stage juveniles; instead, high and low recruitment years 
had similar population levels. They concluded that the 
northcentral GOM blue crab fishery was not recruitment 
limited and that year-class strength was dependent on 
juvenile survival. In the northcentral GOM, there have 
been significant declines in numbers of later stage juve- 
niles in trawl surveys; however, blue crabs at early life 
history stages collected in beam plankton trawls and 
seines do not exhibit similar trends (Riedel et al., 2010). 
Climate interacts with an ever-changing physiograph- 
ic landscape world-wide. Significant downward trends 
in abundance of juvenile blue crabs across the northern 
GOM have occurred over a period characterized by 
drought and unprecedented changes in habitat associ- 
ated with catastrophic storms and the cumulative con- 
sequences of man-made alterations to coastal wetlands 
(Riedel et al., 2010). Recruitment has been adequate and 
numbers of megalopae and early juveniles do not exhibit 
declines. Unlike the fishery in Chesapeake Bay, the 
fishery in the GOM does not suffer from overharvesting 
(Riedel et al., 2010). There is strong evidence that fish- 
ery sustainability is dependent upon juvenile survival. 
In the northcentral GOM, climate and hydrological fea- 
tures operate to structure available habitat in ways that 
affect juvenile survival of blue crabs. Whether the shift 
to a more favorable climate phase would reverse declin- 
ing trends is unknown because it is currently impossi- 
ble to quantitatively account for the influence of chang- 
ing habitats. The results of this work are a starting 
point toward understanding the complex relationship 
between climate, habitat, and fisheries productivity. 
Acknowledgments 
The authors would like to thank C. F. Rakocinski and 
R. R Riedel for their expert advice. We are very grate- 
ful to V. Guillory, K. Ibos, J. Adriance, P. Cook, and M. 
Harbison from the Louisiana Department of Wildlife 
and Fisheries and the personnel from the University 
of Southern Mississippi, Gulf Coast Research Labora- 
tory, Center for Fisheries Research and Development 
for providing us with the fishery independent data from 
the coastal study areas of Louisiana and Mississippi, 
respectively. Appreciation must also be expressed to 
M. G. Williams and C. A. Schloss of the University of 
Southern Mississippi, Gulf Coast Research Laboratory, 
Gunter Library. 
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