The importance of a functional approach on benthic communities for aquaculture environmental assessment: Trophic groups - A polychaete view.

Polychaetes were studied to assess the effect of aquaculture activity on the seafloor. Very high biodiversity of species was recorded associated with aquaculture centres with Cirratulidae, Spionidae and Paraonidae families being the most diverse and abundant families. The spatial distribution of polychaete trophic groups was the best descriptor for detecting changes on the benthos. Surface and subsurface deposit-feeding species dominated the sites closest to the rafts cages, highlighting Capitella capitata and Cirratulus cirratus as opportunistic species. While replacement and species succession were observed with increasing presence of carnivores and omnivores in sites further away from the salmon cages and experiencing less impact. Analyses based on the distance of feeding modes and ecological groups from the disturbance source were better indicators of the impact that the traditional community approach or sediment biogeochemistry. Therefore, functional traits studies should always be considered on environmental assessments of benthic systems impacted by aquaculture.

Bottom trawl fishing footprints on the world's continental shelves.

Bottom trawlers land around 19 million tons of fish and invertebrates annually, almost one-quarter of wild marine landings. The extent of bottom trawling footprint (seabed area trawled at least once in a specified region and time period) is often contested but poorly described. We quantify footprints using high-resolution satellite vessel monitoring system (VMS) and logbook data on 24 continental shelves and slopes to 1,000-m depth over at least 2 years. Trawling footprint varied markedly among regions: from <10% of seabed area in Australian and New Zealand waters, the Aleutian Islands, East Bering Sea, South Chile, and Gulf of Alaska to >50% in some European seas. Overall, 14% of the 7.8 million-km2 study area was trawled, and 86% was not trawled. Trawling activity was aggregated; the most intensively trawled areas accounting for 90% of activity comprised 77% of footprint on average. Regional swept area ratio (SAR; ratio of total swept area trawled annually to total area of region, a metric of trawling intensity) and footprint area were related, providing an approach to estimate regional trawling footprints when high-resolution spatial data are unavailable. If SAR was ≤0.1, as in 8 of 24 regions, there was >95% probability that >90% of seabed was not trawled. If SAR was 7.9, equal to the highest SAR recorded, there was >95% probability that >70% of seabed was trawled. Footprints were smaller and SAR was ≤0.25 in regions where fishing rates consistently met international sustainability benchmarks for fish stocks, implying collateral environmental benefits from sustainable fishing.

Marine debris ingestion by coastal dolphins: what drives differences between sympatric species?

This study compared marine debris ingestion of the coastal dolphins Pontoporia blainvillei and Sotalia guianensis in a sympatric area in Atlantic Ocean. Among the 89 stomach contents samples of P. blainvillei, 14 (15.7%) contained marine debris. For S. guianensis, 77 stomach contents samples were analyzed and only one of which (1.30%) contained marine debris. The debris recovered was plastic material: nylon yarns and flexible plastics. Differences in feeding habits between the coastal dolphins were found to drive their differences regarding marine debris ingestion. The feeding activity of P. blainvillei is mainly near the sea bottom, which increases its chances of ingesting debris deposited on the seabed. In contrast, S. guianensis has a near-surface feeding habit. In the study area, the seabed is the main zone of accumulation of debris, and species with some degree of association with the sea bottom may be local bioindicators of marine debris pollution.

The morphology and structure of the Hannibal Bank fisheries management zone, Pacific Panama using acoustic seabed mapping / Morfología y estructura de la zona especial de manejo de Banco Hannibal, Pacífico de Panamá mediante el uso de sensores remotos acústicos

The Hannibal Bank sits within the Coiba UNESCO World Heritage Site in Pacific Panama and is also a fisheries management zone. Despite the protected status of the area and the importance of the Bank for commercial fish species such as snapper and tuna, the seamount has received no detailed survey except some collection of organisms. This study mapped the major topographic features and complexity of the Hannibal Bank seamount using acoustic remote sensing. A survey area of around 125km² was defined using existing charts and side-scan sonar data were collected during July 2008. A bathymetric output was imported to ArcGIS where a digital bathymetric model and slope map were created. The Benthic Terrain Modeler BTM extension for ArcGIS was used to calculate bathymetric position index and rugosity, and used to create a map of zones representing the various seabed morphology zones. The Hannibal bank is an elongated, triangular guyot flat topped seamount, which ranges in depth from 53m to 416m, covers an area of 76km² and is 14.4km long and 7.1km wide. Hannibal bank is composed of steep slopes, more gentle slopes, top of the seamount, crests elevated ridges at the top of the pinnacles, rugose areas on crests, top of seamount and slope, gullies and pinnacles. The bank is asymmetric in nature with the Northerly side having a relatively gentle slope with gullies across the surface compared to the SouthWest side which is far steeper and more rugose. There are two pinnacles to the North and South East of the bank that range in depth from 180 to 333m. Rocky substrate makes up 22.6km² of the bank and sediment 37.8km². The bank and its steeply sided, rugose areas and pinnacles provide upright structures which can disrupt and topographically enhance currents, increasing productivity. The rugose areas of Hannibal Bank should be primary targets for further research efforts as they may contain corals and their rugosity indicates that these should be some of the highest faunal diversity areas of the bank. Hannibal Bank is likely to come increasing pressure in the future through climate change and fishing and this study has produced valuable information to assist in the future mapping and management of habitats, associated species and fisheries.

El Banco Hannibal se encuentra en Coiba que es Patrimonio de la Humanidad de UNESCO en el Pacífico de Panamá y es una importante zona de pesca. Este estudio evaluó las principales características topográficas y la complejidad de la montaña submarina Banco Hannibal mediante el uso de sensores remotos acústicos. A pesar del estado de protección de la zona y la importancia para las especies comerciales de peces como el pargo y el atún, la montaña submarina no ha tenido ningún estudio detallado salvo alguna colección de organismos. El área de estudio de alrededor de 125km² identificada usando cartas de navegación fue definida usando datos de sonar de barrido lateral durante julio 2008. La información batimétrica fue importada a ArcGIS donde se creó un modelo digital batimétrico DBM y mapa de pendientes. La extensión del ArcGIS Benthic Terrain Modeler BTM se utilizó para calcular el índice de posición batimétrica o BPI pendiente de cada celda relativa a las celdas vecinas y rugosidad. El banco Hannibal es un guyot alargado, triangular montaña submarina plana en parte superior, que se extiende en profundidad desde 53m hasta 416m, tiene una superficie de 76km² y es de 14.4km de largo y 7.1km de ancho. El Banco Hannibal está compuesto por pendientes pronunciadas, pendientes más suaves, parte superior de la montaña submarina, crestas altos relieves en la parte superior, zonas rugosas en las crestas, parte superior de los montes submarinos y pendiente, barrancos y crestas. El banco es asimétrico, con una pendiente relativamente suave y con surcos a través de la superficie en el lado norte en comparación con el lado suroeste que es mucho más pronunciado y más rugoso. Hay dos cumbres al norte y al sureste de la orilla, que varían en profundidad de 180 a 333m. El sustrato rocoso comprende unos 22.6km² del banco y sedimentos 37.8km². El banco y sus caras abruptas, áreas rugosas y pináculos proporcionan estructuras verticales que pueden alterar y mejorar topográficamente las corrientes. Esto se cree produce un afloramiento local que explicaría las mayores agregaciones de peces que son el objetivo de la pesca comercial y deportiva. Es probable que el Banco Hannibal tenga una presión cada vez mayor en el futuro debido al cambio climático y la pesca y este estudio ha producido información valiosa que permite la clasificación de los hábitats para el manejo de las especies asociadas y su pesca, así como la iniciación de la investigación sobre montañas submarinas de Panamá.