+ Site Statistics
+ Search Articles
+ PDF Full Text Service
How our service works
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ Translate
+ Recently Requested

Trophic signatures of small-scale fishing gears: implications for conservation and management



Trophic signatures of small-scale fishing gears: implications for conservation and management



Marine Ecology Progress Series 333: 117-128



We quantified the ecosystem effects of small-scale gears operating in southern European waters (Portugal, Spain, Greece), based on a widely accepted ecosystem measure and indicator, the trophic level (TL). We used data from experimental fishing trials during 1997 to 2000. We studied a wide range of gear types and sizes: (1) gill nets of 8 mesh sizes, ranging from 44 to 80 mm; (2) trammel nets of 9 inner panel mesh sizes, ranging from 40 to 140 mm; and (3) longlines of 8 hook sizes, ranging from Nos. 15 (small) to 5 (large). We used the number of species caught per TL class for constructing trophic signatures (i.e. cumulative TL distributions), and estimated the TL at 25, 50 and 75% cumulative frequency (TL25, TL50, TL75) and the slopes using the logistic function. We also estimated the mean weighted TL of the catches (TLW). Our analyses showed that the TL characteristics of longlines varied much more than those of gill and trammel nets. The longlines of large hooks (Nos. 10, 9, 7, 5) were very TL selective, and their trophic signatures had very steep slopes, the highest mean TL50 values, very narrow mean TL25 to TL75 ranges and mean TLW > 4. In addition, the mean number of TL classes exploited was smaller and the mean TL50 and TLW were larger for the longlines of small hooks (Nos. 15, 13, 12, 11) in Greek than in Portuguese waters. Trammel and gill nets caught more TL classes, and the mean slopes of their trophic signatures were significantly smaller than those of longlines as a group. In addition, the mean number of TL classes exploited, the mean TL50 and the TLW of gill nets were significantly smaller than those of trammel nets. We attribute the differences between longlines of small hooks to bait type, and the differences between all gear types to their characteristic species and size-selectivity patterns. Finally, we showed how the slope and the TL50 Of the trophic signatures can be used to characterise different gears along the ecologically 'unsustainable-sustainable' continuum.

Please choose payment method:






(PDF emailed within 1 workday: $29.90)

Accession: 013275807

Download citation: RISBibTeXText


Related references

Landing characteristics of fishing gears in small-scale tropical coastal fisheries of pelabuhanratu bay, west java and its application for gear management. 2013

Fishing farmers or farming fishers? Fishing typology of inland small-scale fishing households and fisheries management in singkarak lake, west sumatra, indonesia. Environmental Management 52(1): 85-98, 2014

Land degradation assessment by small scale traditional African farmers and implications for sustainable conservation management. Geoforum 25(2): 145-154, 1994

Studies on fishing ground, fishing gears and fishing technique in one-boat medium trawl fishery. Mem Fac Fish Hokkaido Univ 5(1): 1-90, 1957

Study on production of fisheries by small scale fishing boats in sotobo waters i. classification of small scale fishing boats. Journal of the Tokyo University of Fisheries 78(2): 227-242, 1991

Some implications of technical innovations in small scale fishing over the last two decades. Papers, Conference on post war economic development, Ceylon studies seminar, University of Peradeniya: 35, 1980

Fishing gear ; theory and design of fishing gears for deep-sea fishing. 1977

Conservation and management implications of deep-sea coral and fishing effort distributions in the Northeast Pacific Ocean. 2005

Loggerhead turtle by-catch depends on distance to the coast, independent of fishing effort: implications for conservation and fisheries management. Marine Ecology Progress Series 338: 249-256, 2007

Fishing efficiency of an American fishing system for a small-scale tuna longliner. Journal of the Fisheries Society of Taiwan 24(2): 93-101, 1997

Studying small purse-seine vessel fishing behavior with tuna catch data Implications for eastern Pacific Ocean dolphin conservation. Marine Mammal Science aop(aop), 2012

Ferrocement fishing boats: their potential for small-to-medium scale fishing in Lake Malawi. Ferrocement fishing boats: their potential for small to medium scale fishing in Lake Malawi: 70, 1986

Electro-fishing for salmonids in small streams--aspects of the sampling design Fish conservation, fisheries management, Sweden. Report Institute of Freshwater Research: 0) 19-24, 1982

Management challenges of small-scale fishing communities in a protected reef system of Veracruz, Gulf of Mexico. Fisheries Management and Ecology 15(1): 19-26, 2008

Multispecies perspective for small-scale fisheries management: A trophic analysis of La Paz Bay in the Gulf of California, Mexico. Ecological Modelling 201(2): 205-222, 2007