scholarly journals Demersal Assemblages on the Soft Bottoms off the Catalan-Levante Coast of the Spanish Mediterranean

2011 ◽  
Vol 2011 ◽  
pp. 1-16 ◽  
Author(s):  
Mariano García-Rodríguez ◽  
Pere Abelló ◽  
Angel Fernández ◽  
Antonio Esteban
Keyword(s):  
Fisheries Management ◽  
Depth Distribution ◽  
Ecosystem Approach ◽  
Western Mediterranean ◽  
Multispecies Fisheries ◽  
Middle Slope ◽  
Soft Bottoms ◽  
High Species Richness ◽  
Total Species ◽  
Upper Slope

The analysis of 255 bottom trawl samples obtained in annual experimental surveys (2007–2010) along the western Mediterranean shows the existence of five well-defined demersal assemblages that follow a depth distribution: (a) upper shelf assemblages, including two assemblages differentiated by the type of substrate (sand-muddy and terrigenous muddy bottoms); (b) a middle shelf assemblage; (c) an upper slope assemblage; (d) a middle slope assemblage. Faunally, they are dominated by fish (37% of 452 total species), followed by crustaceans (22%), molluscs (17%), echinoderms (9%), and other invertebrates (15%). The assemblages identified showed major alterations on the shelf and shelf edge and less pronounced ones on the upper and middle slope. The average diversity values were more or less high, evidencing the high species richness in the western Mediterranean. The identified assemblages may facilitate future multispecies fisheries management based on an ecosystem approach.

scholarly journals Harvest Strategies for an Ecosystem Approach to Fisheries Management in Western Mediterranean Demersal Fisheries

2017 ◽  
Vol 4 ◽  
Author(s):  
Antoni Quetglas ◽  
Gorka Merino ◽  
Javier González ◽  
Francesc Ordines ◽  
Antoni Garau ◽  
...  
Keyword(s):  
Fisheries Management ◽  
Ecosystem Approach ◽  
Western Mediterranean

scholarly journals Fishing for function: the use of biological traits to evaluate the effects of multispecies fisheries on the functioning of fisheries assemblages

2016 ◽  
Vol 73 (4) ◽  
pp. 1091-1103 ◽  
Author(s):  
Martha Koutsidi ◽  
Evangelos Tzanatos ◽  
Athanassios Machias ◽  
Vassiliki Vassilopoulou
Keyword(s):  
Functional Traits ◽  
Fisheries Management ◽  
Eastern Mediterranean ◽  
Ecosystem Approach ◽  
Purse Seine ◽  
Small Scale ◽  
Biological Traits ◽  
Multispecies Fisheries ◽  
Important Target ◽  
The Relationship

Abstract The Ecosystem Approach to Fisheries Management claims that fisheries management should take into account the ecosystem processes; in that context, it is useful to examine the functional traits of fisheries assemblages. This can be a challenge in multispecies fisheries. We used 21 biological traits of 86 species to investigate the relationship between-species and trait composition and to identify species with rare functional traits. Combining these traits with two catch datasets from the eastern Mediterranean (Patraikos Gulf: small-scale fleet, eastern Ionian Sea: entire multispecies fleet), we investigated whether certain fishing tactics or gears tend to remove specific traits, using multivariate methodologies. Species and traits composition of the catches were related, but an important part of trait variability was not explained by species composition. Rare traits and trait combinations were found for important target or bycatch species. Differences in the traits composition of fishing operations were revealed both between fishing tactics (Patraikos) as well as gears and areas (eastern Ionian); hierarchical clustering and MDS indicated the distinction of purse-seine catches at gear level. SIMPER analysis by trait indicated associations of certain trait categories mainly with purse-seines (at gear level) and longline métiers and a trammel-net métier (at métier level). The identification of rare traits or their combinations can have significant management implications as overfishing of the species with these traits could result in altering assemblage functioning. It seems that the multispecies character of the benthic fisheries results in a balanced trait removal, while management should regulate the effects of purse-seine fisheries on the fisheries assemblage functioning. Further investigation of the functions that fishing may remove from the ecosystem could contribute to understanding the effects of fishing and reveal overlooked aspects useful for the improvement of fisheries management.

Deep-Water Mysids of the Catalan Sea: Species Composition, Bathymetric and Near-Bottom Distribution

1995 ◽  
Vol 75 (1) ◽  
pp. 187-197 ◽  
Author(s):  
J.E. Cartes ◽  
J.C. Sorbe
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Water Column ◽  
Deep Water ◽  
Dominant Species ◽  
Western Mediterranean ◽  
Total Abundance ◽  
Middle Slope ◽  
First Time ◽  
Upper Slope

Deep-water suprabenthic species of Mysidacea were studied in the Catalan Sea (western Mediterranean). Twenty-one samples were taken at depths from 385 to 1859 m, using a Macer-Giroq type sledge. Sixteen mysid species have been collected. Boreomysis arctica was the commonest species and Parapseudomma calloplura, Paramblyops rostrata and Erythrops neapolitana were also notable for their high occurrence. The genus Dactylamblyops, Mysidella biscayensis and Pseudomma affine were recorded for the first time in the Mediterranean. The greatest total abundance of mysids was found over the middle slope. On the upper slope P. calloplura and E. neapolitana formed the dominant species, and deeper B. arctica dominated. Species richness and diversity (H’) declined with increasing depth. The decrease in H’ was attributable to the growing dominance of B. arctica over the middle and lower slopes. Swimming coefficients near the bottom showed intraspecific differences. In general, the species collected inhabit the water column between 0.1 and 0.5 m above the bottom. The bathypelagic species Eucopia hanseni had high swimming coefficients. Amongst the suprabenthic species, B. arctica showed the highest swimming coefficients, and rose from the near-bottom during night on the upper and middle slope stations.

Fish assemblages on the slope in the Catalan Sea (western Mediterranean): influence of a submarine canyon

1994 ◽  
Vol 74 (3) ◽  
pp. 499-512 ◽  
Author(s):  
Constanti Stefanescu ◽  
Beatriz Nin-Morales ◽  
Enric Massuti
Keyword(s):  
Fish Assemblages ◽  
Submarine Canyon ◽  
Demersal Fish ◽  
Western Mediterranean ◽  
Size Distributions ◽  
Large Size ◽  
Fish Weight ◽  
Middle Slope ◽  
Upper Slope ◽  
Ecological Differences

The analysis of 35 bottom trawls taken on the slope in the Catalan Sea (western Mediterranean) has shown the existence of two different demersal fish assemblages occurring on the upper (350–650 m) and middle (1150–1300 m) slope. The middle slope assemblage is characterized by much higher values in some ecological parameters such biomass and mean fish weight, resulting from the dominance of middle to large size species (e.g. Alepocephalus rostratus, Trachyrhynchus trachyrhynchus, Mora mom). On the upper slope two different stations were considered, one inside and the other outside a submarine canyon. Only slight differences were found in species composition, and hence sample and species were not clearly separated by a correspondence analysis. However, some interesting ecological differences exist between these two stations. Much higher values in abundance and biomass inside the canyon were indicative of higher food availability there. Moreover, a drop in mean fish weight was also noted inside the canyon. The analysis of size distributions in the commonest species along the upper slope showed that the submarine canyon acts as a recruiting ground for some of them.

scholarly journals Public Officials’ Knowledge of Advances and Gaps for Implementing the Ecosystem Approach to Fisheries in Chile

2021 ◽  
Vol 13 (5) ◽  
pp. 2703
Author(s):  
Rodrigo A. Estévez ◽  
Stefan Gelcich
Keyword(s):  
Decision Making ◽  
Fisheries Management ◽  
Cost Effective ◽  
Ecosystem Approach ◽  
Social Dimensions ◽  
Public Officials ◽  
Government Officials ◽  
Effective Implementation ◽  
Mandatory Requirement ◽  
Support Decision Making

The United Nations calls on the international community to implement an ecosystem approach to fisheries (EAF) that considers the complex interrelationships between fisheries and marine and coastal ecosystems, including social and economic dimensions. However, countries experience significant national challenges for the application of the EAF. In this article, we used public officials’ knowledge to understand advances, gaps, and priorities for the implementation of the EAF in Chile. For this, we relied on the valuable information held by fisheries managers and government officials to support decision-making. In Chile, the EAF was established as a mandatory requirement for fisheries management in 2013. Key positive aspects include the promotion of fishers’ participation in inter-sectorial Management Committees to administrate fisheries and the regulation of bycatch and trawling on seamounts. Likewise, Scientific Committees formal roles in management allow the participation of scientists by setting catch limits for each fishery. However, important gaps were also identified. Officials highlighted serious difficulties to integrate social dimensions in fisheries management, and low effective coordination among the institutions to implement the EAF. We concluded that establishing clear protocols to systematize and generate formal instances to build upon government officials’ knowledge seems a clear and cost effective way to advance in the effective implementation of the EAF.

scholarly journals Balanced harvesting in fisheries: a preliminary analysis of management implications‡

2015 ◽  
Vol 73 (6) ◽  
pp. 1668-1678 ◽  
Author(s):  
S. M. Garcia ◽  
J. Rice ◽  
A. Charles
Keyword(s):  
Fisheries Management ◽  
Preliminary Analysis ◽  
Fishery Management ◽  
Sustainable Use ◽  
Relative Size ◽  
Implementation Challenges ◽  
Multispecies Fisheries ◽  
Natural Productivity ◽  
Partial Implementation ◽  
Spawning Sites

Abstract Balanced harvest (BH) proposes to distribute a moderate mortality from fishing across the widest possible range of species, stocks, and sizes in an ecosystem, in proportion to their natural productivity so that the relative size and species composition are maintained, in line with the CBD requirement for sustainable use. This proposal has many and not always intuitive implications for fisheries management, e.g. in relation to selectivity, protection of juveniles and spawning sites, models of harvesting strategies, a focus on size and species, the impacts of discarding, aspects of emblematic species and ecosystem services, operational complexity, partial implementation, ecosystem rebuilding, and relations with broader management frameworks. The paper closes with a discussion of BH implementation, concluding that a logical step would be to integrate several separate initiatives to move fisheries into a more ecosystem-conscious context. Implementation challenges will be encountered, but there are lessons to be drawn from fishery ecosystems already close to BH, as in some tropical multispecies fisheries, and further, the implementation challenges are already being taken on in many well-managed fisheries and areas as management begins to address the realities of what ecosystem-based fishery management actually entails.

Seasonality in a taxocoenosis of molluscs from soft bottoms in the Bay of Cádiz (southern Spain)

2001 ◽  
Vol 81 (6) ◽  
pp. 903-912 ◽  
Author(s):  
Jose L. Rueda ◽  
Manuel Fernández-Casado ◽  
Carmen Salas ◽  
Serge Gofas
Keyword(s):  
Species Richness ◽  
Correspondence Analysis ◽  
Dominant Species ◽  
Southern Spain ◽  
Soft Bottom ◽  
Soft Bottoms ◽  
High Species Richness ◽  
Bay Of Cadiz ◽  
Bay Of Cádiz ◽  
Autumn And Winter

The macrofauna of molluscs associated with soft bottoms in the Bay of Cádiz (southern Spain) was studied monthly from February 1994 to January 1996. The number of species (63) is high for a soft bottom and is related to environmental characteristics (growth of macrophytes) and the biogeographical setting of the studied area. Corbula gibba (∼90%) was the dominant species in this taxocoenosis together with the gastropod Nassarius pygmaeus and the bivalves Pandora inaequivalvis, Parvicardium exiguum and Macoma melo. The most frequent species during the two years was also the bivalve Corbula gibba (100%) followed by the gastropods Nassarius pygmaeus, Tricolia tenuis, Rissoa membranacea and the bivalve Macoma melo. Total abundance of the taxocoenosis in both years reached higher values in spring. The dynamics of the ecological indices such as diversity or evenness, and the species richness showed a similar pattern in both years, with low values of diversity and evenness together with high species richness in spring and summer months and the reverse in autumn and winter. The qualitative correspondence analysis of monthly samples shows an ordination related to seasonality in both studied years, however the values of Jaccard's coefficient do not indicate significant boundaries among the monthly samples. The quantitative correspondence analysis shows an ordination and grouping of samples related to the biology of species, particularly with the recruitment of C. gibba, the dominant species. The existence of similar trends in the structure of the taxocoenoses over both years, and the seasonality highlighted by the qualitative correspondence analysis, seems to indicate a certain stability of the ecosystem.

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