Spatial distribution of catch and effort in a fishery for snow crab (<i>Chionoecetes opilio</i>): tests of predictions of the ideal free distribution

Swain, Douglas P.; Wade, Elmer

doi:10.1139/f03-076

Cited by 79 publications

(47 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Harley et al 2001) and could be sensitive to changes in fishing efficiency (e.g. Myers & Cadigan 1995, Hutchings 1996, Swain & Wade 2003 and target species catchability (e.g. Murray & Seed 2010).…”

Section: Speciesmentioning

confidence: 99%

Top-down interactions and temperature control of snow crab abundance in the northwest Atlantic Ocean

Boudreau

Anderson²,

Worm³

2011

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

In much of the northwest Atlantic Ocean, commercially important snow crab Chionoecetes opilio stocks have increased in abundance since the decline and collapse of major groundfish stocks such as Atlantic cod Gadus morhua. We examined 3 hypotheses to explain variation in the abundance of snow crabs across 10 regions: (1) climate control of both species, (2) top-down control of snow crab by cod and (3) bottom-up control of cod by snow crab. We tested these hypotheses by analyzing time series data of cod and crab abundance indices and temperature via meta-analysis of full and partial correlation coefficients. We found that temperature had an opposing effect on the 2 species: snow crab abundance was negatively correlated with temperature at 7 to 10 yr lags, whereas cod and temperature were positively related at 1 to 7 yr lags. Controlling for the effect of temperature, our meta-analysis revealed significant negative correlations of snow crab and cod abundance, with cod leading snow crab by up to a 5 yr lag. This suggests a top-down effect on older juvenile and subadult snow crab. We found no evidence of a bottom-up effect of snow crab on cod. Negative correlations between cod and crab abundance were observed both at the warmer and colder portions of their ranges. These results suggest that snow crab abundance is largely influenced by temperature during the early postsettlement years and becomes increasingly regulated by top-down mechanisms during the years approaching fishery recruitment. The method presented in this paper is generally useful to test ecological hypotheses from time series data, particularly where multiple causal mechanisms are suspected.

show abstract

Section: Speciesmentioning

confidence: 99%

Top-down interactions and temperature control of snow crab abundance in the northwest Atlantic Ocean

Boudreau

Anderson²,

Worm³

2011

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

show abstract

“…The nature of such a relationship can be expected to vary. A positive relationship could arise, particularly in a young fishery, if fish density drives the distribution of fishers (Sutherland 1996, Swain & Wade 2003, Beecham & Engelhard 2007 or, later, if a species benefits from the removal of a competitor or predator targeted by the fishery (Jennings et al 2001, Pinnegar et al 2002, Dulvy et al 2004. A negative relationship could occur when intense fishing severely depletes local populations.…”

Section: Discussionmentioning

confidence: 99%

Effects of an artisanal fishery on non-spawning grouper populations

Molloy¹,

Reynolds²,

Gage³

et al. 2009

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

Many populations of groupers (Teleostei: Serranidae) are overfished, partly because most species form spawning aggregations that are temporally and spatially predictable and therefore easily targeted by fisheries. However, most grouper fisheries operate year-round, thus there can also be high mortality during non-spawning periods. We investigated the impact of fishing around Anguilla, British West Indies, on a commercially important grouper, the red hind Epinephelus guttatus, during the non-breeding season. We combined information on the spatial intensity of the fishery with underwater surveys of groupers to test for associations between fishing intensity and fish size and density across 19 sites. Red hind density was unrelated to fishing intensity but red hinds were larger in areas that were targeted more intensively by fishers. While these results might be taken to suggest that fishing has no negative impacts on red hind demographics, we present evidence from fish markets that fishing intensity on this species during the non-spawning season is high. A variety of mechanisms may mask site-specific negative impacts on density and size of red hinds. In particular, fishers can easily move among sites to track grouper abundance and body size, thereby making it difficult to detect impacts on red hinds during the non-spawning season.

show abstract

“…They concluded that this concept may be true in some fisheries, like in the one that they studied in the English Channel, but does not completely explain all fishermen behaviour. In addition to profit, other stimuli influence the behaviour such as fuel cost, regulations, the fishermen's abilities, the accessibility of a region or weather condition (Hilborn and Kennedy 1992;Prince and Hilborn 1998;Swain and Wade 2003;Alban et al 2004;Salas and Gaertner 2004). However, among these factors profit might be the most determining factor.…”

Section: Economic Pressuresmentioning

confidence: 99%

Modelling the spatio-temporal interplay between North Sea saithe (Pollachius virens) and multiple fleet segments for management evaluation

Simons

Döring

Temming

2014

Aquat. Living Resour.

View full text Add to dashboard Cite

-There is growing interest in bio-economic models as tools for understanding pathways of fishery behaviour, in order to assess the impact on natural resources. Based on 'FishRent', a modelling approach is presented that integrates economics of the fleet, the impact of fishing on stock development and their spatio-temporal interplay. The simulation of species seasonal movements in combination with both observed values and stochastic recruitment allowed analysing the economic response of fleet segments to changes in stock distribution and development. Optimisation of net profits determines the effort adjustment and spatial allocation of fleet segments, which in turn affects the level of catch rates. Effort tended to concentrate where fish abundance was high, but also where fishing costs were low. In simulations with the current management plan spawning stock of North Sea saithe (Pollachius virens) declined below its precautionary reference point. In response fishing far from home ports became expensive and 40% of the initial effort was shifted to areas closer to home ports, but as areas of high fish concentrations were located by the modelled fleet segments catch rates remained high. Changes in seasonal/annual stock distribution, the stock decline and costs influenced the change in fishing effort distributions leading to overestimated catch per unit of effort values that masked the decline of stock abundance.

show abstract

Spatial distribution of catch and effort in a fishery for snow crab (Chionoecetes opilio): tests of predictions of the ideal free distribution

Cited by 79 publications

References 17 publications

Top-down interactions and temperature control of snow crab abundance in the northwest Atlantic Ocean

Top-down interactions and temperature control of snow crab abundance in the northwest Atlantic Ocean

Effects of an artisanal fishery on non-spawning grouper populations

Modelling the spatio-temporal interplay between North Sea saithe (Pollachius virens) and multiple fleet segments for management evaluation

Contact Info

Product

Resources

About