Global Journal of Science Frontier Research: D Agriculture and Veterinary Volume 14 Issue 6 Version 1.0 Year 2014 Type : Double Blind Peer Reviewed International Research Journal Publisher: Global Journals Inc. (USA) Online ISSN: 2249-4626 & Print ISSN: 0975-5896 Trends in the Chamelea Gallina Production from Molise Region (Adriatic Sea, Italy): A Ten-Year Survey By Mariaspina Scopa, Eliana Nerone, Sara Recchi & Nadia Beatrice Barile Istituto Zooprofilattico Sperimentale dell’Abruzzo e del Molise ‘G. Caporale’, Italy Abstract- This study provides a qualitative and quantitative assessment of Chamelea gallina stock in the italian region Molise (Adriatic Sea) in 2003-2012 years. We investigated abundance, biomass and size distr ibution of Clams populations. Reported results showed biomass and abundance fluctuations in several years and at different investigated areas. The areas with greater fishable biomass are those near Trigno and Rio Vivo rivers, especially in 2010- 2012 years. In Both areas, the Clams biomass and density amounts show strong seasonal and annual variations with no detectable seasonal equal trends in several years. In this study, concentrations of sub-commercial size individuals suggesting crowded conditions were never detected. Data analysis also evidence that fishery activity is based almost exclusively on specimens that have just reached minimum commercial size (25-35 mm). However, in both areas, there was a progressive increase in commercial Organisms size; so it is supposable, despite recruitment low rate, a positive trend for population growth. Keywords: chamelea gallina, bivalves, size distribution, resource’s management, adriatic sea. GJSFR-D Classification : FOR Code: 079999 TrendsintheChameleaGallinaProductionfromMoliseRegionAdriaticSeaItalyATenYearSurvey Strictly as per the compliance and regulations of : © 2014. Mariaspina Scopa, Eliana Nerone, Sara Recchi & Nadia Beatrice Barile. This is a research/review paper, distributed under the terms of the Creative Commons Attribution-Noncommercial 3.0 Unported License http://creativecommons.org/licenses/by-nc/3.0/), permitting all non commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Trends in the Chamelea Gallina Production from Molise Region (Adriatic Sea, Italy): A Ten-Year Survey Mariaspina Scopa α, Eliana Nerone σ, Sara Recchi ρ & Nadia Beatrice Barile Ѡ Abstract- This study provides a qualitative and quantitative some studies (NOJIMA & RUSSO, 1989; MASSÈ, 1971) ass essment of Chamelea gallina stock in the italian region have shown that the growth rate of individuals can differ 2014 Molise (Adriatic Sea) in 2003-2012 years. We investigated among sites, and age classes may have a slightly r abundance, biomass and s ize distr ibution of Clams different range. Nevertheless, according to the Council ea populations. Reported results showed biomass and Y Regulation (EC) No 1967/2006, 25 mm is the minimum abundance fluctuations in several years and at different investigated areas. The areas with greater fishable biomass commercial size allowed. 7 ar e those near Trigno and R io Vivo rivers, especially in 2010- Studies on the ecology and physiology of 2012 years. In Both areas, the Clams biomass and density Chamelea gallina are scarce, but some information on amo unts show s trong seaso nal and annual variations with no environmental factors influencing its abundance may be detectable seasonal equal trends in several years. In this gained from several studies carried out since the mid- V study, concentrations of sub-commercial s ize individuals 1970s in the northern Adriatic in response to VI suggesting crowded conditio ns were never detected. Data phenomena such as “red tides”, as well as “marine analysis also evidence that fishery activity is based almost ue ersion I s exclusively on specimens that have just reached minimum snow” which could negatively impact both human health s I commercial s ize (25-35 mm). However, in both areas, there and tourism (ROMANELLI et al., 2009). X was a progressive increase in commercial Organisms size; so It is known that the growth of bivalves is XIV it is s upposable, despite recr uitment low rate, a pos itive trend primarily dependent on food availability, water for population growth. temperature and salinity, and sediment characteristics Keywords: chamelea gallina, bivalves, size distribution, (BROOKS et al., 1991; ORBAN et al., 2002; ORBAN et resource’s management, adriatic sea. al., 2004). ) D ) Chamelea gallina feeds on phytoplankton and I. Introduction other suspended material; for its growth the dissolved he striped venus clam Chamelea gallina is a nutrients amount and the nitrogen and phosphorus ratio bivalve, lamellibranch, filter feeder belonging to the are also relevant. Veneridae family; it lives in high beds density Research Volume T Water temperature has a dominant role in hosting the “biocenosis of fine well-sorted sands” o growth rates: values below 10 C strongly slow or avoid (SFBC) as described by Peres & Picard (1964), at growth (FROGLIA, 2000), while very high temperatures depths between 1 and 15 m. It is particularly present in measured on the sea bottom (28 o C) during summer Frontier the wild, mainly on the central and northern Adriatic, have detrimental effects, reducing energy absorption where the sea water is rich in mineral salts and organic and above all increasing energy expenditure via matter, due to inputs of rivers like Po and others. The respiration (RAMÓN & RICHARDSON,1992; Science target species is gonocorist with a spawning season MOSCHINO & MARIN, 2006). of approximately comprised between April and October Dissolved oxygen is a further abiotic factor with 1-2 peak(s) (FROGLIA, 1975 a, b; CASALI, 1984; influencing bivalves growth: hypoxia, anoxia and high VALLI et al., 1985; KELLER et al., 2002). The earliest temperatures during summer seasons can lead to Journal mature individuals are 13-15 mm (MARANO et al., 1982; increased ammonia concentrations which may CORDISCO et al., 2003), though full maturity is reached contribute to negative growth values in exposed when clams are 20-25 mm and about two years old . animals, as demonstrated in R. decussatus by SOBRAL Global In Adriatic area the clams reach a size of 15-20 & WIDDOWS (1997). mm at the beginning of the first year of life, An additional source of stress for C. gallina is approximately 25 mm a year later, and 32-34 mm in the reproduction, which starts from spring and continues third year (POGGIANI et al., 1973; FROGLIA, 1975a; until late summer, with a reproductive peak in July MARANO et al., 1982; ARNERI et al., 1995). However, (NOJIMA & RUSSO, 1989). C. gallina, similarly to many other bivalve species, shows increased respiration rates Author α σ ρ Ѡ : Istituto Zooprofilattico Sperimentale dell’Abruzzo e del during the reproductive period (WIDDOWS, 1978; Molise “G.Caporale”- Centro Sperimentale Regionale della Pesca ed Acquacoltura, Termoli, Italy. e -mails: [email protected], [email protected] IGLESIAS & NAVARRO, 1991; URRUTIA et al., 1999). ©2014 Global Journals Inc. (US) Trends in the Chamelea Gallina Production from Molise Region (Adriatic Sea, Italy): A Ten-Year Survey In the 1970s the development of clam fishery and are generally comprised between 8°C (winter) and based on hydraulic dredges led to an over-exploitation 28 °C (summer). of the resource with a dramatic decrease in density of b) Sampling and analyses clams populations and an increase in mortality events Clam samples were dredged along the Molise’s from the 90s onwards (Ministry of Agriculture, 1998). In coastline, comprised between Trigno and Saccione the late 1970s the fishery yielded 80,000-100,000 metric rivers, in 2003-2012 years at regular time intervals. tons while actually it doesn’t exceed 20,000 metric tons. Seasonal samplings were conducted according to At the beginning of the 80s, general rules were monitoring plans approved by the Molise region and defined for limiting fishing licenses and establishing the weather and sea water conditions permitting. maximum catches allowed in order to minimize the The survey area was divided into four zones: resource depletion. Trigno, Sinarca, Rio vivo e Saccione. In recent years, clam fishery management has Sampling was carried out in collaboration with 2014 been entrusted directly to fishermen’ associations who fishermen’s cooperative. r plan fishing activity on the basis of available resources, The catches were performed by hydraulic set fishing days per week, work’s daily hours, periods of Yea dredges with 11 mm grid, along transects perpendicular catch suspension and daily catch amounts. to the coast at a distance of 250-500 m from coastline, 8 In the Italian region of Molise it exists a unique dredging 200-300 m long stretches. All sampling points association named Co.Ge.Vo. and established in 1995, were located with GPS positioning system. with ten clam vessels.This association, authorized by the For each catch, all sampled material collected Ministry of Agriculture and Forestry to manage the into the dredge was weighted and a subsample, V resource Chamelea gallina, has as main objective the rapresentative of total individuals, was prelevated, enhancement, protection and safeguard of clam VI placed in net bags and labelled. After collection, animals populations through the establishment of planting and were transported within about an hour to the laboratory sue ersion I s restocking areas, the monitoring of catches effort, and in a cool box. the arrangement of periodic alternation between work In laboratory, at first, organisms with open or and rest among fishermen. damaged shell were discarded. The antero-posterior The present study evaluates populations of lenght (L) of the shells was measured using a 0.1 mm Chamelea gallina along Molise’s coastline in terms of precision calliper, and it was defined size distribution on biomass and size distribution, recruiment abundance, in the basis of lenght measurements. ) order to provide useful informations for better resource Popolutation distribution was assessed in D ) management and efficient production planning by clams respect to clams’ size and age, considering three associations.