AUTHOR=Hamame Madeleine , Ortiz Paula 

TITLE=Assessment of Exploitation Intensity of Commercial Species and Associated Benthic Communities, in Chilean Marine Management Areas of North Patagonia

JOURNAL=Frontiers in Marine Science

VOLUME=Volume 8 - 2021

YEAR=2022

URL=https://www.frontiersin.org/journals/marine-science/articles/10.3389/fmars.2021.635756

DOI=10.3389/fmars.2021.635756

ISSN=2296-7745

ABSTRACT=The Aysen region of Chile, has had limited studies on the effectiveness of management and exploitation areas of benthic resources, and performance relative to open access areas in this region has never been evaluated. We evaluated seven management areas (MAs) and five open access areas (OAAs) for exploitation intensity of three commercial species (Concholepas concholepas, Loxechinus albus and Ameghinomya antiqua) together with characterization of the benthic community. Indicators based on size, density and weight were used to evaluate exploitation intensity of commercial species. Associated benthic communities were evaluated. We found a high species richness and a community structure with low variability between MAs and OAAs. Low densities and small sizes  of C. concholepas  suggest high exploitation intensity in both MAs and OAAs. In this context, a permanent ban to harvest C. concholepas within OAAs may need to be reevaluated since with no enforcement and monitoring, the exploitation status of this species remains unclear. L. albus in most areas were absent in the harvestable sizes, which could be indicating high exploitation intensity in both regimes. High densities and small sizes of C. concholepas and L. albus in some MAs, indicated a potential recruitment zones which bears further investigation. A. antiqua, showed better conditions than other commercial species evaluated, with no significant differences in densities and size-based indicators when comparing OAAs and MAs. Benthic communities were dominated numerically by the Echinoidea class in both MAs and OAAs. High densities of sea urchins co-ocurring with low coverage of macroalgae found in MAs-Gala could indicate that a sea urchin barren was dominant during the study period. On the other hand, high densities of Cosmasterias lurida, a predatory sea star, in conjunction with low densities of C. concholepas in most of the studied areas suggested that a shift in predator roles is occurring. No differences were estimated in terms of fisheries indicators and benthic community structure across the two management regimes, suggesting the poor performance of MAs. Our data also support the need to improve monitoring of MAs especially with respect to associated benthic community incorporating a broader spatial scale.