An alert system for triggering different levels of coastal management urgency: Tunisia case study using rapid environmental assessment data.

Rapid environmental assessment (REA) involves scoring abundances of ecosystems/species groups and magnitude of pressures, concurrently, using the same logarithmic (0-6) assessment scale. We demonstrate the utility of REA data for an alert system identifying different levels of coastal management concern. Thresholds set for abundances/magnitudes, when crossed, trigger proposed responses. Kerkennah, Tunisia, our case study, has significant natural assets (e.g. exceptional seagrass and invertebrate abundances), subjected to varying levels of disturbance and management concern. Using REA thresholds set, fishing, green algae/eutrophication and oil occurred at 'low' levels (scores 0-1): management not (currently) necessary. Construction and wood litter prevailed at 'moderate' levels (scores 2-4): management alerted for (further) monitoring. Solid waste densities were 'high' (scores 5-6): management alerted for action; quantities of rubbish were substantial (20-200 items m⁻¹ beach) but not unprecedented. REA is considered a robust methodology and complementary to other rapid assessment techniques, environmental frameworks and indicators of ecosystem condition.

Size and hematological impact of the splenic erythrocyte reservoir in rainbow trout,Oncorhynchus mykiss.

Fish were sampled individually, at rest, following air exposures of up to 8 min, during recovery from a 5 min air exposure or after a 5 minute chase. The spleen was photographedin vivo at rest and following 5 min air exposure in one fish. The effect of individual versus serial sampling from the same tank and of MS222 anaesthesia was also examined. Spleen hemoglobin content (SpHb), spleen somatic index (100 × spleen weight/body weight; SSI), blood hemoglobin concentration (Hb), and hematocrit (Ht), were measured. Mean cell hemoglobin concentration (MCHC), erythrocyte reservoir size, and relative contributions of reservoir release, erythrocyte swelling, and plasma water loss to hemoconcentration were calculated. The splenic reservoir contained 0.54 g Hb/kg body (21% of total body Hb), most of which it released between 1 and 3 minutes after the onset of air exposure. The spleen released more than 95% of the erythrocytes it contained at rest within 8 min. The release accounted for 31% of the 5.65 g/dl rise in Hb and 23% of the 26.6% observed increase in Ht after 8 minutes of air exposure. The balance of the increase was caused by erythrocyte swelling and fluid shifts reducing plasma volume. Animals exercised for 5 min showed changes similar to those in fish air exposed for 5 min. Recovery of all parameters was complete in 3 to 6 h, with the exception of MCHC which recovered in 30 min. Serial sampling produced a decrease in SpHb, and R1Wt and induced a significant hemoconcentration. MS222 did not cause erythrocyte release, but failed to prevent it after handling. Many previous reports of Ht and Hb in resting fish are probably high because they were taken under conditions that would cause the spleen to release its contents.

Hurricane Allen's Impact on Jamaican Coral Reefs.

Coral reefs of north Jamaica, normally sheltered, were severely damaged by Hurricane Allen, the strongest Caribbean hurricane of this century. Immediate studies were made at Discovery Bay, where reef populations were already known in some detail. Data are presented to show how damage varied with the position and orientation of the substraturn and with the shape, size, and mechanical properties of exposed organisms. Data collected over succeeding weeks showed striking differences in the ability of organisms to heal and survive.