Effects of habitat patchiness on American lobster movement across a gradient of predation risk and shelter competition

Predation of offspring is the main cause of reproductive failure in many species, and the mere fear of offspring predation shapes reproductive strategies. Yet, natural predation risk is ubiquitously variable and can be unpredictable. Consequently, the perceived prospect of predation early in a reproductive cycle may not reflect the actual risk to ensuing offspring. An increased variance in investment across offspring has been linked to breeding in unpredictable environments in several taxa, but has so far been overlooked as a maternal response to temporal variation in predation risk. Here, we experimentally increased the perceived risk of nest predation prior to egg-laying in seven bird species. Species with prolonged parent-offspring associations increased their intra-brood variation in egg, and subsequently offspring, size. High risk to offspring early in a reproductive cycle can favour a risk-spreading strategy particularly in species with the greatest opportunity to even out offspring quality after fledging.

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Predation risk during the early life history periods of fishes: separating the effects of size and age

Marine Ecology Progress Series ◽

10.3354/meps111105 ◽

1994 ◽

Vol 111 ◽

pp. 105-114

Author(s):

DR Bertram ◽

WC Leggett

Keyword(s):

Life History ◽

Predation Risk ◽

Early Life ◽

Early Life History

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Growth of juvenile American lobster Homarus americanus in a changing environment

Marine Ecology Progress Series ◽

10.3354/meps11854 ◽

2016 ◽

Vol 557 ◽

pp. 177-187 ◽

Cited By ~ 8

Author(s):

MD McMahan ◽

DF Cowan ◽

Y Chen ◽

GD Sherwood ◽

JH Grabowski

Keyword(s):

Homarus Americanus ◽

American Lobster ◽

Changing Environment

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Predicting bycatch hotspots based on suitable habitat derived from fishery-independent data

Marine Ecology Progress Series ◽

10.3354/meps13302 ◽

2020 ◽

Vol 641 ◽

pp. 159-175

Author(s):

J Runnebaum ◽

KR Tanaka ◽

L Guan ◽

J Cao ◽

L O’Brien ◽

...

Keyword(s):

Habitat Suitability ◽

Mixed Model ◽

Linear Mixed Model ◽

Gulf Of Maine ◽

Homarus Americanus ◽

Management Tool ◽

American Lobster ◽

Suitable Habitat ◽

Climate Conditions ◽

Suitability Index

Bycatch remains a global problem in managing sustainable fisheries. A critical aspect of management is understanding the timing and spatial extent of bycatch. Fisheries management often relies on observed bycatch data, which are not always available due to a lack of reporting or observer coverage. Alternatively, analyzing the overlap in suitable habitat for the target and non-target species can provide a spatial management tool to understand where bycatch interactions are likely to occur. Potential bycatch hotspots based on suitable habitat were predicted for cusk Brosme brosme incidentally caught in the Gulf of Maine American lobster Homarus americanus fishery. Data from multiple fisheries-independent surveys were combined in a delta-generalized linear mixed model to generate spatially explicit density estimates for use in an independent habitat suitability index. The habitat suitability indices for American lobster and cusk were then compared to predict potential bycatch hotspot locations. Suitable habitat for American lobster has increased between 1980 and 2013 while suitable habitat for cusk decreased throughout most of the Gulf of Maine, except for Georges Basin and the Great South Channel. The proportion of overlap in suitable habitat varied interannually but decreased slightly in the spring and remained relatively stable in the fall over the time series. As Gulf of Maine temperatures continue to increase, the interactions between American lobster and cusk are predicted to decline as cusk habitat continues to constrict. This framework can contribute to fisheries managers’ understanding of changes in habitat overlap as climate conditions continue to change and alter where bycatch interactions could occur.

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