Performance of baited underwater video for estimating abundance of spiny lobsters

Baited underwater video (BUV) is increasingly been used to sample fish species but lobsters are potentially good candidates for sampling with BUV as they are attracted to bait due to their scavenging habits. We built a cost effective BUV system to sample Palinurus elephas, a Mediterranean deep-water lobster. Camera deployments were performed at the Columbretes Islands MPA. We compared the standard method of estimating abundance with BUV, by recording the maximum number (Nmax) of individuals at any one point on the tape, with the estimated true number of lobsters having attended the bait (Ntot). We found it possible to use images of unique body patterns for identifying individuals over time. The highest Nmax - 6 lobsters in the field of view - was lower than the total number of lobsters estimated by identifying individuals in all three recordings - total of 7 to 11 individual lobsters. This highlights the extent of underestimation of abundance derived from Nmax estimates (Mean Nmax = 4 as opposed to Ntot= 8.6 by tracking individuals). Measurement of lobster size was trouble free with the coefficient of variation of all measurements being low. However, all measurements were biassed due to calibration problems related to lobster height above the bait bag. Taking into account the relatively low cost of the units, coupled with the ability of this system to work to depths impractical for visual surveys, we propose that this non-intrusive method will be useful for sampling deep water lobster

Coastal meroplanktonic larval stages of peninsula de Llevant natural reserve determined with light traps

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Performance of Baited Underwater Video: Does It Underestimate Abundance at High Population Densities?

Funding: This work was supported by a grant from the Spanish National Plan for Scientific and Technological Research and Innovation, the RECMARE project (CTM2012-36982 MAR) and by the SGP (Spanish Ministry of Agriculture, Environment and Fisheries) for the ERICOL project. The South Australian Research Institute provided inkind funding support.Abstract Video survey techniques are now commonly used to estimate animal abundance under the assumption that estimates relate to true abundance, a key property needed to make video a valid survey tool. Using the spiny lobster Palinurus elephas as our model organism, we evaluate the effectiveness of baited underwater video (BUV) for estimating abundance in areas with widely different population density. We test three BUV abundance metrics and compare the results with an independently obtained abundance index from trammel-net surveys (Trammel). Video metrics used to estimate relative abundance include a value for total number of individuals per recording (TotN), the traditional maximum number of fish observed in a single video frame (MaxN) and the recently suggested alternative, the average of the mean MaxN from 5-minute periods throughout the duration of the recording (MeanN). This is the first video study of a wild population to include an estimate for TotN. Comparison of TotN with the other two BUV relative abundance metrics demonstrates that both of the latter lack resolution at high population densities. In spite of this, the three BUV metrics tested, as well as the independent estimate Trammel, distinguished high density areas from low density areas. Thus they could all be used to identify areas of differing population density, but MaxN and MeanN would not be appropriate metrics for studies aimed at documenting increases in abundance, such as those conducted to assess marine protected area effectiveness, as they are prone to sampling saturation. We also demonstrate that time of first arrival (T1) is highly correlated with all of the abundance indices,suggesting T1 may be a potentially useful index of abundance. However, these relationships require further investigation as our data suggests T1 may also become sampling-saturated as lobster abundance increases.Publicad

Exploration of the inter-annual variability and multi-scale environmental drivers of European spiny lobster, Palinurus elephas (Decapoda: Palinuridae) settlement in the NW Mediterranean

Determining the drivers of key ecological processes of commercial marine species is important to acquire basic and essential knowledge for fisheries management and conservation. Here we report on a long-term monitoring of the settlement of the European spiny lobster, Palinurus elephas, the most commercially important spiny lobster species in the Mediterranean and north-eastern Atlantic. Densities of recently settled individuals (early benthic juveniles –EBJs) were recorded annually, as an approximation to annual settlement, from 2000 to 2016 (17 years) in three zones of the north-western Mediterranean: Catalonia (CAT), the Columbretes Islands (COL), and the Balearic Islands (BAL). Settlement, the end point that integrate most of the variability occurred during dispersion, is a complex ecological process governed by the interaction of biotic and abiotic factors that can be in turn influenced by the atmospheric and oceanographic conditions. Using linear regression of the size structure of EBJs, we demonstrate that settlement occurs synchronously in the three study zones. Densities of EBJs were handled as time series, and regression analysis revealed that CAT and COL covaried significantly, but none of them with BAL. Therefore, CAT and COL were analysed together using generalized linear model and much of their joint variability was explained by the mesoscale oceanographic index IDEA. Settlement in BAL showed a different pattern, explained by the joint effect of the atmospheric oscillations NAO and WEMO. Complexity of P. elephas settlement cannot be fully accounted neither for CAT-COL nor for BAL because settlement seems be driven by more complex unknown multi-factorial processes. Therefore, further studies are necessary to gain insight into other factors that allow short-or medium-term predictions of settlement. Expanding the study area across the Mediterranean would also allow establishing a complete knowledge of the ecology of the species applicable to the management of the fishery.Versión del edito

Temporal dynamics and role of benthic habitat for the Mediterranean slipper lobster Scyllarides latus in a National Park

Populations of large large decapods have diminished due to intense fishing pressure and habitat modification along the widely inhabited coast. During the last decade some of the well established marine protected areas (MPAs) in the Western Mediterranean have led to growing densities of one of the most sought after large decapods, the slipper lobster Scyllarides latus (Latreille, 1803). A four year monitoring study was conducted to assess seasonal dynamics and habitat preference of S. latus in the Cabrera Archipelago National Park. Sampling was carried out through underwater visual census on rocky habitats at 0 - 50 m depth. The species may be found in caves, under boulders, and on walls and slopes at depths of up to 35 m, showing a preference for caves at 5 to 20 m depth. These hábitats provide diverse shelter types that are used during the daily period of trophic inactivity. S latus has a marked seasonality with highest densities occurring in late spring, and they disappear almost entirely from rocky coastal habitats in mid-summer. Knowledge of the preferred habitats and spatial pattern of the species is needed for implementing appropriate management schemes to stimulate their recover

Informe Proyecto ERCA "Estudio del efecto reserva en el Parque Nacional Marítimo Terrestre del Archipiélago de Cabrera". Año 2006

El estudio del efecto reserva en el Parque Nacional Marítimo Terrestre del Archipiélago de Cabrera, (proyecto ERCA del IEO) que se inició en 1996, tiene como objetivo general evaluar los cambios espacio-temporales en composición específica, abundancia y estructura demográfica del poblamiento íctico litoral atribuibles a las medidas de gestión pesquera adoptadas. La consecución de este objetivo se aborda desde dos metodologías complementarias: i) directamente por censos visuales en inmersión, e ii) indirectamente mediante el estudio de las capturas obtenidas por la pesca artesanal (única actividad extractiva permitida en el PN). Al inicio del proyecto se planteó la necesidad de conocer el patrón de explotación (descripción de artes y aparejos, zonas de pesca y estacionalidad de las pesquerías artesanales) debido a la falta de datos en el área de estudio. Este conocimiento permite evaluar posibles cambios en la distribución espacial y en el tipo de pesquerías que se realizan en la zona. Este año y en apoyo a la gestión del PNMTAC, se ha iniciado en el marco del proyecto ERCA, el estudio de las poblaciones de cigarrón o langosta real, Scyllarides latus, especie de la que apenas existe información sobre su distribución, características biológicas y poblacionales en el Mediterráneo occidental. Por último y desde 2005 el PNMTAC, es una de las reservas marinas incluidas en el estudio de la poblaciones de langosta roja, Palinurus elephas, dentro Convenio SGPM-IEO.Centro Oceanográfico de Baleares (IEO

Revisión de los efectos de la protección en las áreas marinas protegidas: conocimiento y deficiencias actuales

This work was carried out with financial support from the Commission of the European Community, specific RTD program 'Specific Support to Policies', SSP–2003–006539 'European Marine Protected Areas as Tools for Fisheries Management and Conservation (EMPAFISH)'.The effectiveness of marine protected areas (MPAs) and the conservation of marine environments must be based on reliable information on the quality of the marine environment that can be obtained in a reasonable timeframe. We reviewed studies that evaluated all aspects related to the effectiveness of MPAs in order to describe how the studies were conducted and to detect fields in which research is lacking. Existing parameters used to evaluate the effectiveness of MPAs are summarised. Two–hundred and twenty–two publications were reviewed. We identified the most commonly used study subjects and methodological approaches. Most of the studies concentrated on biological parameters. Peer reviewed studies were based on control vs. impact design. BACI and mBACI designs were used in very few studies. Through this review, we have identified gaps in the objectives assigned to MPAs and the way in which they have been evaluated. We suggest some guidelines aimed at improving the assessment of the effects of protection in MPAs.La efectividad de las áreas marinas protegidas (AMPs) y la conservación del medio ambiente marino debe basarse en información fiable sobre la calidad del medio marino que pueda obtenerse en un plazo de tiempo razonable. Se revisaron estudios que evalúan aspectos relacionados con la efectividad de las AMPs con el fin de describir cómo se realizaron los estudios y detectar donde existen vacíos en la investigación. En este estudio se enumeran los parámetros existentes para evaluar la efectividad de las AMPs. Se revisaron 224 publicaciones. Identificamos los objetos de estudio más utilizados y los enfoques metodológicos. La mayoría de los estudios se centran en el estudio de parámetros biológicos. Los estudios publicados se basaron en el diseño control frente a impacto. En muy pocos estudios se utilizaron diseños de muestreo BACI y mBACI. A través de esta revisión, se han identificado deficiencias en los objetivos de las AMPs y en la manera como han sido evaluados. Como conclusión sugerimos algunas pautas para mejorar la evaluación de los efectos de la protección en estas zonas

Review of the effects of protection in marine protected areas: current knowledge and gaps

The effectiveness of marine protected areas (MPAs) and the conservation of marine environments must be based on reliable information on the quality of the marine environment that can be obtained in a reasonable timeframe. We reviewed studies that evaluated all aspects related to the effectiveness of MPAs in order to describe how the studies were conducted and to detect fields in which research is lacking. Existing parameters used to evaluate the effectiveness of MPAs are summarised. Two–hundred and twenty–two publications were reviewed. We identified the most commonly used study subjects and methodological approaches. Most of the studies concentrated on biological parameters. Peer reviewed studies were based on control vs. impact design. BACI and mBACI designs were used in very few studies. Through this review, we have identified gaps in the objectives assigned to MPAs and the way in which they have been evaluated. We suggest some guidelines aimed at improving the assessment of the effects of protection in MPAsRevisión de los efectos de la protección en las áreas marinas protegidas: conocimiento y deficiencias actuales.— La efectividad de las áreas marinas protegidas (AMPs) y la conservación del medio ambiente marino debe basarse en información fiable sobre la calidad del medio marino que pueda obtenerse en un plazo de tiempo razonable. Se revisaron estudios que evalúan aspectos relacionados con la efectividad de las AMPs con el fin de describir cómo se realizaron los estudios y detectar donde existen vacíos en la investigación. En este estudio se enumeran los parámetros existentes para evaluar la efectividad de las AMPs. Se revisaron 224 publicaciones. Identificamos los objetos de estudio más utilizados y los enfoques metodológicos. La mayoría de los estudios se centran en el estudio de parámetros biológicos. Los estudios publicados se basaron en el diseño control frente a impacto. En muy pocos estudios se utilizaron diseños de muestreo BACI y mBACI. A través de esta revisión, se han identificado deficiencias en los objetivos de las AMPs y en la manera como han sido evaluados. Como conclusión sugerimos algunas pautas para mejorar la evaluación de los efectos de la protección en estas zonasPublicado

Estudio de la biología y ecología de Scyllarides latus en el Parque Nacional Marítimo Terrestre del Archipiélago de Cabrera. Implicaciones para la gestión de la especie en las Islas Baleares

El proyecto “Latus 2006 – 2009” desarrollado en el Parque Nacional Marítimo Terrestre del Archipiélago de Cabrera ha tenido como objetivo estudiar los distintos aspectos de la biología y ecología de Scyllarides latus necesarios para diseñar medidas de gestión específicas que aseguren la recuperación y conservación de la especie. En concreto se ha identificado la dinámica de la población (abundancia y demografía), los hábitats preferenciales y la movilidad/ fidelidad de la especie. Asimismo se ha determinado el ciclo reproductor y se ha realizado una primera aproximación al conocimiento del patrón de crecimiento en el medio natural. Para la consecución de estos objetivos se han aplicado técnicas de evaluación directa (censos visuales en inmersión) y técnicas de marcado-recaptura clásicas. El estudio se ha llevado a cabo en hábitats rocosos entre 0 y 50 m de profundidad en 15 zonas del Parque Nacional.Centro Oceanográfico de Baleares (IEO) y Dirección General de Pesca del Govern de les Illes Balear