scholarly journals Nonconsumptive effects of a range‐expanding predator on juvenile lobster ( Homarus americanus ) population dynamics

Ecosphere ◽  
2019 ◽  
Vol 10 (10) ◽  
Author(s):  
Marissa D. McMahan ◽  
Jonathan H. Grabowski
Keyword(s):  
Population Dynamics ◽  
Homarus Americanus ◽  
Nonconsumptive Effects

scholarly journals A model-based approach to incorporate environmental variability into assessment of a commercial fishery: a case study with the American lobster fishery in the Gulf of Maine and Georges Bank

2019 ◽  
Vol 76 (4) ◽  
pp. 884-896 ◽  
Author(s):  
Kisei R Tanaka ◽  
Jie Cao ◽  
Burton V Shank ◽  
Samuel B Truesdell ◽  
Mackenzie D Mazur ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Habitat Suitability ◽  
Environmental Variability ◽  
Homarus Americanus ◽  
Assessment Model ◽  
American Lobster ◽  
Fishing Mortality ◽  
Model Based ◽  
Stock Assessments ◽  
Envelope Model

Abstract Changes in bottom-up forcing are fundamental drivers of fish population dynamics. Recent literature has highlighted the need to incorporate the role of dynamic environmental conditions in stock assessments as a key step towards adaptive fishery management. Combining a bioclimate envelope model and a population dynamic model, we propose a model-based approach that can incorporate ecosystem products into single-species stock assessments. The framework was applied to a commercially important American lobster (Homarus americanus) stock in the Northwest Atlantic. The bioclimate envelope model was used to hindcast temporal variability in a lobster recruitment habitat suitability index (HSI) using bottom temperature and salinity. The climate-driven HSI was used to inform the lobster recruitment dynamics within the size-structured population dynamics model. The performance of the assessment model with an environment-explicit recruitment function is evaluated by comparing relevant assessment outputs such as recruitment, annual fishing mortality, and magnitude of retrospective biases. The environmentally-informed assessment model estimated (i) higher recruitment and lower fishing mortality and (ii) reduced retrospective patterns. This analysis indicates that climate-driven changes in lobster habitat suitability contributed to increased lobster recruitment and present potential improvement to population assessment. Our approach is extendable to other stocks that are impacted by similar environmental variability.

Growth of juvenile American lobster Homarus americanus in a changing environment

2016 ◽  
Vol 557 ◽  
pp. 177-187 ◽  
Author(s):  
MD McMahan ◽  
DF Cowan ◽  
Y Chen ◽  
GD Sherwood ◽  
JH Grabowski
Keyword(s):  
Homarus Americanus ◽  
American Lobster ◽  
Changing Environment

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

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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