Combining Telephone Surveys and Fishing Catches Self-Report: The French Sea Bass Recreational Fishery Assessment

International audienceFisheries statistics are known to be underestimated, since they are mainly based on information about commercial fisheries. However, various types of fishing activities exist and evaluating them is necessary for implementing effective management plans. This paper assesses the characteristics and catches of the French European sea bass recreational fishery along the Atlantic coasts, through the combination of large-scale telephone surveys and fishing diaries study. Our results demonstrated that half of the total catches (mainly small fish) were released at sea and that the mean length of a kept sea bass was 46.6 cm. We highlighted different patterns of fishing methods and type of gear used. Catches from boats were greater than from the shore, both in abundance and biomass, considering mean values per fishing trip as well as CPUE. Spearfishers caught the highest biomass of sea bass per fishing trip, but the fishing rod with lure was the most effective type of gear in terms of CPUE. Longlines had the highest CPUE value in abundance but not in biomass: they caught numerous but small sea bass. Handlines were less effective, catching few sea bass in both abundance and biomass. We estimated that the annual total recreational sea bass catches was 3,173 tonnes of which 2,345 tonnes were kept. Since the annual commercial catches landings were evaluated at 5,160 tonnes, recreational landings represent 30% of the total fishing catches on the Atlantic coasts of France. Using fishers' self-reports was a valuable way to obtain new information on data-poor fisheries. Our results underline the importance of evaluating recreational fishing as a part of the total amount of fisheries catches. More studies are critically needed to assess overall fish resources caught in order to develop effective fishery management tools

Number of scientific papers citing the term “recreational fisheries” from 1990 until now.

<p>Data derived from the research platform “Web of Knowledge” (<a href="http://www.webofknowledge.org" target="_blank">www.webofknowledge.org</a>).</p

The sea bass-specific survey: followed sampling design.

<p>The sea bass-specific survey: followed sampling design.</p

Mean weight and abundance of sea bass caught by recreational fishers from boats and from the shore.

<p>Dark grey: caught sea bass; Medium grey: kept sea bass; Light grey: released sea bass; Black bars: confidence interval (α = 0.95).</p

Annual recreational catch estimates of European sea bass in France (Atlantic coasts).

<p>Medium grey: kept amount; Light grey: released amount.</p

Trace metal elements and organic contaminants are differently related to the growth and body condition of wild European sea bass juveniles

International audienceChemical contaminants are one of the causes of the ongoing degradation of coastal and estuarine nurseries, key functional habitats in which the juveniles of many marine species grow. As chemical contaminants can cause a decrease in the energy available and induce defence mechanisms reducing the amount of energy allocated to life history traits, quantifying their effect on the fitness of juvenile fish is key to understand their population-level consequences. However, these effects are primarily estimated experimentally or in the wild but on a limited number of contaminants or congeners that do not reflect the wide variety of chemical contaminants to which juvenile fish are exposed. To address this issue, we measured concentrations of 14 trace metal elements (TMEs) and bioaccumulative organic contaminants (OCs) in European sea bass juveniles (1-year-old) from three major French nurseries (Seine, Loire and Gironde estuaries). We tested the hypotheses that (i) levels and profiles of contaminants differed among studied nurseries, and ii) fish growth and body condition (based on morphometric measurements and muscle C:N ratio) were lower in individuals with higher contaminant concentrations. Multivariate analyses showed that each nursery had distinct contaminant profiles for both TMEs and OCs, confirming the specific contamination of each estuary, and the large array of contaminants accumulated by sea bass juveniles. Increasing concentrations in some TMEs were associated to decreased growth, and TMEs were consistently related to lower fish body condition. The effect of OCs was more difficult to pinpoint possibly due to operational constraints (i.e., analyses on pooled fish) with contrasting results (i.e., higher growth and decreased body condition). Overall, this study shows that chemical contaminants are related to lower fish growth and body condition at an early life stage in the wild, an effect that can have major consequences if sustained in subsequent ages and associated with a decline in survival and/or reproductive success

European sea bass kept and released by recreational fishers.

<p>Solid circle: kept sea bass; Filled triangle point down: released sea bass; Legal size: minimum legal catch length; Recommended size: length generally recommended by French recreational fishery federations.</p

Percentage of fishing gear used for catching sea bass, from the shore and from boats.

<p>Percentage of fishing gear used for catching sea bass, from the shore and from boats.</p

Mean, minimum and maximum observed fishing duration per type of gear, and number of fishing operations declared using the considered gear.

<p>Mean, minimum and maximum observed fishing duration per type of gear, and number of fishing operations declared using the considered gear.</p

Mean weight and abundance of sea bass caught per gear type and fishing trip.

<p>Medium grey: kept sea bass; Light grey: released sea bass; Black bars: confidence interval (α = 0.95).</p