Quantifying long-term discards from Queensland’s (Australia) east Coast otter trawl fishery

Abstract This article estimated the weight of annual discards in the Queensland east coast otter trawl fishery. Discards data were analysed using three generalized linear mixed models to derive adjusted discard rates, expressed as kg per retained catch, kg per boat day, and kg per area swept by trawls, respectively. Model explanatory terms included trawl fishing sector, presence/absence of bycatch reduction devices (BRDs), lunar phase, and whether the data were obtained from commercial vessels during their normal fishing activities or during research charters. Adjusted discard rates were then used to derive three estimates of annual discards and the average used to examine a long-term discard trends from 1988 to 2014. Total discards declined significantly from a peak of approximately 67 000 t in 1997 to approximately 21 000 t from 2011 to 2014, largely due to a decline in fishing effort, and to a lesser degree, the effects of BRDs that were mandated in the fishery in the early 2000s.

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Use of avoidance behaviours to reduce the economic impacts of the EU Landing Obligation: the case study of a mixed trawl fishery

ICES Journal of Marine Science ◽

10.1093/icesjms/fsz032 ◽

2019 ◽

Vol 76 (6) ◽

pp. 1554-1566

Author(s):

Fabien Pointin ◽

Fabienne Daurès ◽

Marie-Joëlle Rochet

Keyword(s):

Temporal Distribution ◽

Grid Method ◽

Fishing Effort ◽

Economic Losses ◽

Otter Trawl ◽

Trawl Fishery ◽

Nested Grid ◽

Fishing Practices ◽

The Eu

Abstract The EU Landing Obligation (LO) is designed to reduce bycatch (i.e. unwanted catch) through more selective fishing practices, such as avoidance behaviours which consist in allocating fishing effort to other species, fishing grounds or seasons. Incentives for fishers to change their behaviours depend on their economic performances as well as their ability to avoid bycatch. Changes in economic performances under the LO are evaluated based on cost and revenue equations. The nested grid method is then used to explore the spatial and temporal distribution of landings and discards, and to suggest alternative effort allocation to avoid bycatch. This article is focussed specifically on the French otter trawl fishery in the eastern English Channel and southern North Sea. Results suggest that under the LO the choke species problem will curtail fishing activities earlier in the year, leading to significant economic losses. In the absence of significant quota top-ups (at least 75%), a change in fishing practices consisting in reducing overall bycatch by 30% is insufficient to reduce losses. With a particular attention to choke species, more economically efficient avoidance strategies can be found thanks to the nested grid method.

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Estimated catch and mortality of sea turtles from the East Coast Otter Trawl Fishery of Queensland, Australia

Biological Conservation ◽

10.1016/0006-3207(95)00025-y ◽

1995 ◽

Vol 74 (3) ◽

pp. 157-167 ◽

Cited By ~ 25

Author(s):

J.B. Robins

Keyword(s):

East Coast ◽

Sea Turtles ◽

Otter Trawl ◽

Trawl Fishery

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Reproductive characteristics and per-recruit analyses of blue warehou (Seriolella brama): implications for the South East Fishery of Australia

Marine and Freshwater Research ◽

10.1071/mf00022 ◽

2001 ◽

Vol 52 (4) ◽

pp. 575 ◽

Cited By ~ 8

Author(s):

Ian A. Knuckey ◽

K. P. Sivakumaran

Keyword(s):

Egg Production ◽

East Coast ◽

Gonadosomatic Index ◽

Fork Length ◽

Size At Maturity ◽

Current Management ◽

Spawning Period ◽

Gill Net ◽

Trawl Fishing

Monthly samples of commercial catches of S. brama were collected between May 1996 and December 1997 in three regions of the fishery:off the east coast of Victoria; eastern Tasmania; and western Bass Strait. Sex ratio, gonadosomatic index, macroscopic and histological development, size at maturity and fecundity were estimated and combined with data on growth and mortality to perform per-recruit analyses. The main spawning period was during winter–spring and there was evidence of spawning in each of the three regions. Blue warehou reach maturity at 30–40 cm fork length. They have a determinate annual fecundity and spawn around three batches of eggs during a season. Eggs-per-recruit analyses revealed maximum egg production at ~40 cm (4–5 years) in an unfished population. Gill-net fishing, which targets fish >45 cm, was less likely to affect the relative eggs-per-recruit in a population than trawl fishing, which catches a wider range of smaller fish. These results are discussed in light of the current management arrangements in the fishery and will be used in models to assess the effect of fishing on the long-term sustainability of the blue warehou.

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Biology and population dynamics of by-catch fish species of the bottom trawl fishery in the western Mediterranean

Mediterranean Marine Science ◽

10.12681/mms.812 ◽

2014 ◽

Vol 15 (3) ◽

pp. 613 ◽

Cited By ~ 3

Author(s):

F. ORDINES ◽

M.T. FARRIOLS ◽

J. LLEONART ◽

B. GUIJARRO ◽

A. QUETGLAS ◽

...

Keyword(s):

Population Analysis ◽

Conservation Status ◽

Fishing Effort ◽

Western Mediterranean ◽

Distribution Range ◽

Bottom Trawl ◽

Trawl Fishery ◽

Virtual Population ◽

Trawl Fishing ◽

By Catch

The teleosts Chelidonichthys cuculus, Trigloporus lastoviza, Serranus cabrilla and Trachinus draco, are important by-catch species, in terms of landed biomass and commercial value, from the continental shelf bottom trawl fishery off the Balearic Islands (western Mediterranean). The main biological parameters of these species were calculated from monthly biological samplings, and were used along with three years pseudo-cohorts (2008-2010) obtained from monitoring on-board of the bottom trawl fleet, to assess their exploitation level through Virtual Population Analysis (VPA) and Yield per Recruit (Y/R) analysis. Time series of fishery independent indicators based on MEDITS surveys data such as the evolution of the abundance and biomass, the distribution range, and the Conservation Status of Fish b (CSFb), were also analyzed. All four species analyzed showed growth overfishing. The reductions of the fishing effort required to reach the Y/RF0,1 reference point were lower, 66-73% depending on the species, to those reported for the target species M. merluccius (87%), but higher than that reported for M. surmuletus (53%), in the study area in the period 2000-2010. The abundance and biomass, and the distribution range did not show any trend for the period 2001-2011, whereas the CSFb showed signs of recovery that may be due to the displacement of the trawl fishing effort from the shelf to the slope during the last decade. Our results underline the necessary incorporation of monitoring and assessment of by-catch species to the management of fisheries as their populations can show a more pronounced overexploitation than target ones.

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Effort distribution and catch patterns adjacent to temperate MPAs

ICES Journal of Marine Science ◽

10.1016/j.icesjms.2005.04.005 ◽

2005 ◽

Vol 62 (6) ◽

pp. 1150-1167 ◽

Cited By ~ 196

Author(s):

Steven A. Murawski ◽

Susan E. Wigley ◽

Michael J. Fogarty ◽

Paul J. Rago ◽

David G. Mountain

Keyword(s):

Spatial Distribution ◽

Protected Area ◽

Marine Protected Area ◽

Spatial Coherence ◽

Fishing Effort ◽

Data Sources ◽

Otter Trawl ◽

Closed Area ◽

Trawl Fishing ◽

Average Revenue

Abstract We evaluated the spatial distribution of otter trawl fishing effort and catches resulting from the imposition in 1994 of year-round and seasonal groundfish closed areas off the NE USA. Vessel locations were available from logbooks, vessel monitoring system (VMS) data from many of the largest vessels, and from observer records. There was high spatial coherence between VMS- and observer-derived trawling locations. Prior to establishment, 31% of trawl effort (1991–1993) occurred within the 22 000 km2 of area that would eventually be closed year-round. In 2001–2003 about 10% of effort targeting groundfish was deployed within 1 km of the marine protected area (MPA) boundaries, and about 25% within 5 km. Density gradients, consistent with spill-over from MPAs, were apparent for some species. Average revenue per hour trawled was about twice as high within 4 km of the boundary, than for more distant catches, but the catch variability was greater nearer closed area boundaries. Seasonal closed areas attracted more fishing effort after opening than prior to closure even while average cpue was the same or lower. Spatial resolution of traditional data sources (e.g., logbooks) was too crude to discern detailed MPA-related effects, as revealed by high-resolution vessel positions from VMS and catch data obtained by observers.

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A long term (1949-2010) study of catch and effort in Israeli trawl fishery, Eastern Mediterranean Sea

Acta Adriatica ◽

10.32582/aa.58.1.13 ◽

2017 ◽

Vol 58 (1) ◽

pp. 157-164 ◽

Cited By ~ 1

Author(s):

Daniel Golani ◽

Dor Edelist ◽

Amit Lerner ◽

Oren Sonin ◽

Uzi Motro

Keyword(s):

Eastern Mediterranean ◽

Fishing Effort ◽

Maximum Sustainable Yield ◽

Mediterranean Coast ◽

Sustainable Yield ◽

Yield Model ◽

Eastern Mediterranean Sea ◽

Trawl Fishery ◽

Engine Power

The trawl fishery of the Mediterranean coast of Israel was analyzed vis á vis catch and fishing effort for the years 1949-2010. The Maximum Sustainable Yield (MSY) was calculated using the Fox surplus-yield model and was found to be 1,413 ton per annum using 1,415 units of effort (fishing days X engine power divided by 1000). Only during nine years (1997-2005) did fishing effort exceed the value for which the yield is the MSY by an average of 184.9 units of effort, but the yield was similar to that of the previous years. During 10 years the catch exceeded the MSY by an average of 153±119 tons. This result was used to justify the “freezing” of the local trawl fleet at the beginning of the 1990’s.

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Spatial Changes in Trawl Fishing Effort in Response to Footrope Diameter Restrictions in the U.S. West Coast Bottom Trawl Fishery

North American Journal of Fisheries Management ◽

10.1577/m02-098 ◽

2003 ◽

Vol 23 (3) ◽

pp. 693-702 ◽

Cited By ~ 11

Author(s):

Robert W. Hannah

Keyword(s):

West Coast ◽

Fishing Effort ◽

Bottom Trawl ◽

Trawl Fishery ◽

Spatial Changes ◽

Trawl Fishing ◽

The U.S

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Reproductive parameters of rhinobatid and urolophid batoids taken as by-catch in the Queensland (Australia) east coast otter-trawl fishery

Journal of Fish Biology ◽

10.1111/jfb.13020 ◽

2016 ◽

Vol 89 (2) ◽

pp. 1208-1226 ◽

Cited By ~ 3

Author(s):

P. M. Kyne ◽

A. J. Courtney ◽

I. P. Jacobsen ◽

M. B. Bennett

Keyword(s):

East Coast ◽

Otter Trawl ◽

Reproductive Parameters ◽

Trawl Fishery ◽

By Catch

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Environmental and fisheries effects on Gracilechinus acutus (Echinodermata: Echinoidea) distribution: is it a suitable bioindicator of trawling disturbance?

ICES Journal of Marine Science ◽

10.1093/icesjms/fss102 ◽

2012 ◽

Vol 69 (8) ◽

pp. 1457-1465 ◽

Cited By ~ 7

Author(s):

J. M. González-Irusta ◽

A. Punzón ◽

A. Serrano

Keyword(s):

Habitat Preferences ◽

Fishing Effort ◽

Otter Trawl ◽

Sediment Type ◽

Trawl Fishery ◽

Sediment Types ◽

Initial Hypothesis ◽

Wet Weight ◽

Using Data ◽

The Impact

AbstractGonzález-Irusta, J. M., Punzón, A., and Serrano, A. 2012. Environmental and fisheries effects on Gracilechinus acutus (Echinodermata: Echinoidea) distribution: is it a suitable bioindicator of trawling disturbance? – ICES Journal of Marine Science, 69: . Habitat preferences of Gracilechinus acutus in the southern Bay of Biscay were studied using data from autumn bottom-trawl surveys. Wet weight and number of specimens of G. acutus were obtained and related to environmental variables (depth, sediment type, and organic matter percentage) at each haul and to trawl fishing effort. With this information and the otter trawl effort data, the environmental requirements and the impact of the trawl fishery on G. acutus populations were analysed. Although the species was present in all depth strata and all sediment types studied, it had clear habitat preferences, as greater abundances and mean weight values were found at depths ranging from 71 to 200 m and in bottom sediments dominated by coarse and medium sands. The effect of disturbance by trawling on this echinoid was significant and clearly negative. Seabeds exposed to higher trawling disturbance showed lower values of urchin abundance and smaller urchins than areas with lower disturbance. Results of the present study confirm the initial hypothesis of the suitability of using this urchin as a bioindicator of trawling impact but only in areas with appropriate environmental conditions, highlighting the importance of attaining a wider knowledge on the essential habitat of the species.

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