Brown muscle disease and Manila clam Ruditapes Philippinarum dynamics in Arcachon Bay, France

Brown Muscle Disease (BMD) affects Manila clam Ruditapes philippinarum. It was described for the first time in 2005 in Arcachon Bay, France. The pathology consists in a progressive necrosis of the posterior adductor muscle, valve gaping, clam migration to the sediment surface, and death. This study aims to quantify the prevalence of BMD in the bay and to evaluate the effect of BMD on Manila clam dynamics. The prevalence was assessed on 50 stations spread within Arcachon Bay. About 62% of Manila clam habitat surface was infected by BMD. A survey of buried and surface clams was conducted from November 2006 to March 2008 in Lanton, a site infected by BMD. Modal progression analysis separated confidently cohorts from 2003 to 2005 recruitments. This pathology only affected adult clams (>25 mm, >2 years). For both buried and surface individuals, shell length was significantly correlated with BMD infection. Surface clams had prevalence (67%) higher than buried clams (23%) and showed greater mortality rate after 15 d in running water: 82% against 12% for buried individuals. The final disease index (FDI) and the condition index (CI) were monthly evaluated on 50 clams located at each position in the sediment. CI displayed a significant decrease after BMD's infection from light to severe disease stages. Length data analysis through Bhattacharya's method (FISAT II software) allowed identifying four cohorts. The 2003s cohort enabled to calculate mortality rate that was 39% for 5 months and to estimate that BMD was responsible of 95% of that mortality. The temperature was certainly an important factor in BMD transmission, because cohort dynamics results argued that BMD developed during spring and summer

ICLARM software projects: back to the future

The different computer softwares developed by the International Center for Living Aquatic Resources (ICLARM) and its functions and uses in fisheries science are presented

ELEFAN I and II live on screen

Computer programs, Fish

A program for constructing length-converted growth curves when growth is seasonal

Growth curves, GOTCH.A (computer programme), Fishery biology, Computer programs

A regional database management system—the fisheries resource information system and tools (FiRST): Its design, utility and future directions

South and Southeast Asian countries have undertaken demersal trawl surveys to measure the fisheries potential of their waters throughout the 20th century. However, ensuring full use of, and easy access to the resulting data is a challenge in developing countries. The “Fisheries Resource Information System and Tools” (FiRST) was developed through a regional collaborative effort across eight South and Southeast Asian counties to meet these needs. FiRST is a data management system for scientific trawl survey data and includes data summary and visualization tools, an analytical routine to estimate biomass, and data import/export modules. The FiRST software has also facilitated the establishment of a regional database, ‘Trawl Base’, which contains more than 20,000 hauls or stations from scientific trawl surveys in 10 countries conducted between 1926 and 1995. The regional database is an important regional resource for coastal fisheries management complementing national fisheries catch statistics

Life‐cycle responses of a Mediterranean non‐migratory cyprinid species, the Northern Iberian chub (Squalius carolitertii Doadrio, 1988), to streamflow regulation.

Streamflow is considered a driver of interspecific and intraspecific life‐history differences among freshwater fish. Therefore, dams and related flow regulation can have deleterious impacts on their life cycles. The main objective of this study was to assess existing differences in the growth and reproduction patterns of a non‐migratory fish species (the Northern Iberian chub, Squalius carolitertii, Doadrio, 1988), between nonregulated and regulated watercourses. For 1 year, samples were collected from two populations of Iberian chub, inhabiting rivers with nonregulated and regulated flow regimes. Flow regulation for water storage promoted changes in chub's condition, duration of spawning, fecundity, and oocyte size. However, this non‐migratory species was less responsive to streamflow regulation than other native potamodromous species. Findings from this study are important to understand changes imposed by regulated rivers and can be used to support the implementation of suitable river management practices

SUNLIGHT: a computer program for calculation of daily solar radiation

This paper presents an algorithm and software (available from ICLARM) for estimating the possible amount of sunlight that may fall on any location of the earth, any day of the year, as might be required for ecological modelling

A Low-level Geographic Information System for coastal zone management, with applications to Brunei Darussalam: Part I: The concept and its design elements

This contribution is the first part of a four-part series documenting the development of B:RUN, a software program which reads data for common spreadsheets and presents them as low-resolution maps of slates and processes. The program emerged from a need which arose during a project in Brunei Darussalam for a 'low level' approach for researchers to communicate findings as efficiently and expeditiously as possible. Part I provides a overview of the concept and design elements of B:RUN. Part II will highlight results of the economics components of the program evaluating different fishing regimes, sailing distances from ports and fleet operating costs. Environmental aspects will be presented in Part III in the form of overlay maps. Part IV will summarize the implications of B:RUN results to coastal and fishery resources management in Brunei Darussalam and show how this approach can be adapted to other coastlines and used as a teaching and training tool. The following three parts will be published in future editions of Naga, the ICLARM Quarterly. The program is available through ICLARM

A low-level geographic information system for coastal zone management with applications to Brunei Darussalam: Part III:: simulation and tracking oil spills

B:RUN is a low-level GIS software designed to help formulate options for the management of the coastal zone of Brunei Darussalam. This contribution presents the oil spill simulation module of B:RUN. This simple module, based largely on wind and sea surface current vector parameters, may be helpful in formulating relevant oil spill contingency plans. It can be easily adapted to other areas, as can the B:RUN software itself