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Interactions between a Trawl fishery and spatial closures for biodiversity conservation in the Great Barrier Reef World Heritage Area, Australia.

Grech A, Coles R - PLoS ONE (2011)

Bottom Line: The past decade has seen the implementation of conservation and fisheries management strategies to reduce the impact of the ECOTF on the seabed and improve biodiversity conservation.The decline in effort as a result of fishing industry structural adjustment, increasing variable costs and business decisions of fishers is likely to continue a trend to fish only in the most productive areas.This will provide protection for most benthic habitats without any further legislative or management intervention.

View Article: PubMed Central - PubMed

Affiliation: Fisheries Queensland, Department of Employment, Economic Development and Innovation, Cairns, Queensland, Australia. alana.grech@jcu.edu.au

ABSTRACT

Background: The Queensland East Coast Otter Trawl Fishery (ECOTF) for penaeid shrimp fishes within Australia's Great Barrier Reef World Heritage Area (GBRWHA). The past decade has seen the implementation of conservation and fisheries management strategies to reduce the impact of the ECOTF on the seabed and improve biodiversity conservation. New information from electronic vessel location monitoring systems (VMS) provides an opportunity to review the interactions between the ECOTF and spatial closures for biodiversity conservation.

Methodology and results: We used fishing metrics and spatial information on the distribution of closures and modelled VMS data in a geographical information system (GIS) to assess change in effort of the trawl fishery from 2001-2009 and to quantify the exposure of 70 reef, non-reef and deep water bioregions to trawl fishing. The number of trawlers and the number of days fished almost halved between 2001 and 2009 and new spatial closures introduced in 2004 reduced the area zoned available for trawl fishing by 33%. However, we found that there was only a relatively minor change in the spatial footprint of the fishery as a result of new spatial closures. Non-reef bioregions benefited the most from new spatial closures followed by deep and reef bioregions.

Conclusions/significance: Although the catch of non target species remains an issue of concern for fisheries management, the small spatial footprint of the ECOTF relative to the size of the GBRWHA means that the impact on benthic habitats is likely to be negligible. The decline in effort as a result of fishing industry structural adjustment, increasing variable costs and business decisions of fishers is likely to continue a trend to fish only in the most productive areas. This will provide protection for most benthic habitats without any further legislative or management intervention.

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Related in: MedlinePlus

Proportion (%) of the reef, non-reef and deep bioregions of the Great Barrier Reef World Heritage Area (GBRWHA) zoned available to trawl fishing, and the proportion of reef, non-reef and deep bioregions where trawl fishing was conducted and conducted more than once (i.e. > five hours per year) from 2001–2009.Trawl fishing predominantly occurred in non-reef habitats; 18.5–28.6% of non-reef bioregions were trawled from 2001–2009 (Table S1). Non-reef bioregions had the largest reduction of area zoned available for trawl fishing after new spatial closures were introduced in 2004, followed by the deep and reef bioregions (Table S1). Less than half of the area zoned available for trawl fishing in non-reef, reef and deep bioregions was actually trawled from 2001–2009.
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pone-0021094-g004: Proportion (%) of the reef, non-reef and deep bioregions of the Great Barrier Reef World Heritage Area (GBRWHA) zoned available to trawl fishing, and the proportion of reef, non-reef and deep bioregions where trawl fishing was conducted and conducted more than once (i.e. > five hours per year) from 2001–2009.Trawl fishing predominantly occurred in non-reef habitats; 18.5–28.6% of non-reef bioregions were trawled from 2001–2009 (Table S1). Non-reef bioregions had the largest reduction of area zoned available for trawl fishing after new spatial closures were introduced in 2004, followed by the deep and reef bioregions (Table S1). Less than half of the area zoned available for trawl fishing in non-reef, reef and deep bioregions was actually trawled from 2001–2009.

Mentions: We found that between 2001 and 2009, trawl fishing predominantly occurred in non-reef bioregions and 23 of the 32 non-reef bioregions were trawled in 2009 (Table S1). Non-reef bioregions had the largest reduction of area zoned available for trawl fishing (Table S1; Figure 4) after new spatial closures were introduced in 2004 (49,182 km2; 19.8% of non-reef bioregions). This was followed by the deep bioregions (9,099 km2, 11.3%) and reef bioregions (613 km2, 3.1%). 27.7% of non-reef bioregions were trawled in 2001, declining to 18.5% in 2009. There was little change in the area of deep bioregions trawled between 2001 and 2009 (9.5% down to 8.9%) and only 3 of the 8 deep bioregions were exposed to trawling in 2009 (Table S1). 1.5% of reef bioregions were trawled in 2001 declining to 0.2% in 2009. Bioregions that experienced the greatest decline in the proportion of area trawled between 2001–2009 included the central open lagoon reefs (59.8%–0.0%), inner shelf seagrass (81.3%–45.2%), inner mid shelf lagoon (88.0–57.7%) and the coastal southern fringing reefs (30.4–1.0%; Table S1). Bioregions that had >40% of their total area trawled in 2009 were all non-reef (inshore muddy lagoon, inner shelf seagrass, inner mid shelf lagoon and the Capricorn Bunker lagoon; Table S1).


Interactions between a Trawl fishery and spatial closures for biodiversity conservation in the Great Barrier Reef World Heritage Area, Australia.

Grech A, Coles R - PLoS ONE (2011)

Proportion (%) of the reef, non-reef and deep bioregions of the Great Barrier Reef World Heritage Area (GBRWHA) zoned available to trawl fishing, and the proportion of reef, non-reef and deep bioregions where trawl fishing was conducted and conducted more than once (i.e. > five hours per year) from 2001–2009.Trawl fishing predominantly occurred in non-reef habitats; 18.5–28.6% of non-reef bioregions were trawled from 2001–2009 (Table S1). Non-reef bioregions had the largest reduction of area zoned available for trawl fishing after new spatial closures were introduced in 2004, followed by the deep and reef bioregions (Table S1). Less than half of the area zoned available for trawl fishing in non-reef, reef and deep bioregions was actually trawled from 2001–2009.
© Copyright Policy
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC3113906&req=5

pone-0021094-g004: Proportion (%) of the reef, non-reef and deep bioregions of the Great Barrier Reef World Heritage Area (GBRWHA) zoned available to trawl fishing, and the proportion of reef, non-reef and deep bioregions where trawl fishing was conducted and conducted more than once (i.e. > five hours per year) from 2001–2009.Trawl fishing predominantly occurred in non-reef habitats; 18.5–28.6% of non-reef bioregions were trawled from 2001–2009 (Table S1). Non-reef bioregions had the largest reduction of area zoned available for trawl fishing after new spatial closures were introduced in 2004, followed by the deep and reef bioregions (Table S1). Less than half of the area zoned available for trawl fishing in non-reef, reef and deep bioregions was actually trawled from 2001–2009.
Mentions: We found that between 2001 and 2009, trawl fishing predominantly occurred in non-reef bioregions and 23 of the 32 non-reef bioregions were trawled in 2009 (Table S1). Non-reef bioregions had the largest reduction of area zoned available for trawl fishing (Table S1; Figure 4) after new spatial closures were introduced in 2004 (49,182 km2; 19.8% of non-reef bioregions). This was followed by the deep bioregions (9,099 km2, 11.3%) and reef bioregions (613 km2, 3.1%). 27.7% of non-reef bioregions were trawled in 2001, declining to 18.5% in 2009. There was little change in the area of deep bioregions trawled between 2001 and 2009 (9.5% down to 8.9%) and only 3 of the 8 deep bioregions were exposed to trawling in 2009 (Table S1). 1.5% of reef bioregions were trawled in 2001 declining to 0.2% in 2009. Bioregions that experienced the greatest decline in the proportion of area trawled between 2001–2009 included the central open lagoon reefs (59.8%–0.0%), inner shelf seagrass (81.3%–45.2%), inner mid shelf lagoon (88.0–57.7%) and the coastal southern fringing reefs (30.4–1.0%; Table S1). Bioregions that had >40% of their total area trawled in 2009 were all non-reef (inshore muddy lagoon, inner shelf seagrass, inner mid shelf lagoon and the Capricorn Bunker lagoon; Table S1).

Bottom Line: The past decade has seen the implementation of conservation and fisheries management strategies to reduce the impact of the ECOTF on the seabed and improve biodiversity conservation.The decline in effort as a result of fishing industry structural adjustment, increasing variable costs and business decisions of fishers is likely to continue a trend to fish only in the most productive areas.This will provide protection for most benthic habitats without any further legislative or management intervention.

View Article: PubMed Central - PubMed

Affiliation: Fisheries Queensland, Department of Employment, Economic Development and Innovation, Cairns, Queensland, Australia. alana.grech@jcu.edu.au

ABSTRACT

Background: The Queensland East Coast Otter Trawl Fishery (ECOTF) for penaeid shrimp fishes within Australia's Great Barrier Reef World Heritage Area (GBRWHA). The past decade has seen the implementation of conservation and fisheries management strategies to reduce the impact of the ECOTF on the seabed and improve biodiversity conservation. New information from electronic vessel location monitoring systems (VMS) provides an opportunity to review the interactions between the ECOTF and spatial closures for biodiversity conservation.

Methodology and results: We used fishing metrics and spatial information on the distribution of closures and modelled VMS data in a geographical information system (GIS) to assess change in effort of the trawl fishery from 2001-2009 and to quantify the exposure of 70 reef, non-reef and deep water bioregions to trawl fishing. The number of trawlers and the number of days fished almost halved between 2001 and 2009 and new spatial closures introduced in 2004 reduced the area zoned available for trawl fishing by 33%. However, we found that there was only a relatively minor change in the spatial footprint of the fishery as a result of new spatial closures. Non-reef bioregions benefited the most from new spatial closures followed by deep and reef bioregions.

Conclusions/significance: Although the catch of non target species remains an issue of concern for fisheries management, the small spatial footprint of the ECOTF relative to the size of the GBRWHA means that the impact on benthic habitats is likely to be negligible. The decline in effort as a result of fishing industry structural adjustment, increasing variable costs and business decisions of fishers is likely to continue a trend to fish only in the most productive areas. This will provide protection for most benthic habitats without any further legislative or management intervention.

Show MeSH
Related in: MedlinePlus