Genetic structuring of immature loggerhead sea turtles (Caretta caretta) in the Mediterranean Sea reflects water circulation patterns

The analysis of mitochondrial DNA in loggerhead sea turtles (Caretta caretta) from eight foraging grounds in the Mediterranean and the adjoining Atlantic revealed deep genetic structuring within the western Mediterranean. As a consequence, the foraging grounds off the North-African coast and the Gimnesies Islands are shown to be inhabited mainly by turtles of the Atlantic stocks, whereas the foraging grounds off the European shore of the western Mediterranean are shown to be inhabited mainly by turtles from the eastern Mediterranean rookeries. This structuring is explained by the pattern of sea surface currents and water masses and suggests that immature loggerhead sea turtles entering the western Mediterranean from the Atlantic and the eastern Mediterranean remain linked to particular water masses, with a limited exchange of turtles between water masses. As the north of the western Mediterranean comprises mostly individuals from the highly endangered eastern Mediterranean rookeries, conservation plans should make it a priority to reduce the mortality caused by incidental by-catch in these areas.     

Role of salps in the flux of organic matter to the bottom of the Ligurian Sea

Sediment-trap samples were collected during and after the occurrence of a salp (Salpa fusiformis) bloom in the Bay of Villefranche, Mediterranean Sea, in April/May 1985. Large amounts of organic aggregates and faecal pellets were collected during the bloom. The aggregates were rich in carbohydrates and mineral grains and had similar rates of sedimentation (900 to 2 100 m d^-1) to those of the faecal pellets (1 000 to 2 000 m d^-1). The results of mineralogical and organic chemical analyses indicate the potential effect of these mucus-rich aggregates on local biogeochemical fluxes.     

Further studies of short-term variation in the pigment composition of a spring phytoplankton bloom

Phytoplankton sampled at the chlorophyll maximum during the spring bloom at Loch Ewe, Scotland during 1986, were analysed using high-performance liquid chromatography for chloropigments and carotenoids. The day-to-day proportions of the pigments remained relatively stable throughout the bloom, with good preservation of chlorophyll a even at the sediment surface. Chlorophyllide a and phaeophorbide a appeared towards the end of the bloom. The major carotenoids remained stable throughout the bloom, but became rapidly degraded on sedimentation under the oxic conditions. The pigment data is related to the nutrient status of the bloom, when slow steady growth occurred without nutrient limitation. These data contrast sharply with data from the 1983 spring bloom at Loch Ewe when acute nutrient limitation took place.     

Does male harassment of females contribute to reproductive synchrony in the grey seal by affecting maternal performance?

We investigated the possibility that male harassment of lactating females differed in relation to time of birth in the grey seal, Halichoerus grypus, on Sable Island, Nova Scotia. This was done by comparing the frequency of male disturbances, maternal performance and pup growth for females that either gave birth during the peak of the pupping season or after the peak. Of the females, 58% gave birth in a 7-day period near the beginning of the pupping period, when the operational sex ratio was 2–4 females per male. Late in the pupping period the operational sex ratio reversed to about 1 female for every 2 males. The relative frequency of disturbances by males was significantly greater for late-pupping mothers than for peak-pupping ones (1.9 vs. 1.4 encounters/h). Females that gave birth late also were disturbed by males 3 times more often than females that gave birth during the peak (3.4 vs. 1.1 % of observation time). Late-pupping mothers spent 22% less time suckling (4.0 vs. 5.1 % of observation time), had 30% slower growing pups (1.7 vs. 2.4 kg/d), and weaned pups that were 16% lighter (45.6 vs. 54.0 kg). The effect of birth time on pup mass gain and weaning mass was not attributable to factors such as maternal mass, pup birth mass or pup sex. We conclude that the reduced maternal performance is likely the result of the increased male harassment. As reduced weaning mass can lead to reduced juvenile survival, male harassment may have contributed to the enhanced reproductive synchrony in this species.     

The analysis of free chlorine in the presence of nitrogenous organic compounds

Comparative analyses for aqueous chlorine using Standard Methods indicated that in chlorinated solutions containing nitrogenous organic compounds, none of these methods gave a reliable measurement of free available chlorine. Examination of the cyanuric acid-aqueous chlorine system showed that combined chlorine reacted as if it were free chlorine in all the Standard Methods. The implication of these studies for water and wastewater chlorination is that in waters containing nitrogenous organic compounds, N-Chloro compounds form which may result in an overestimation of the disinfecting potential of the added chlorine, when free chlorine is measured by Standard Methods.     

Minimizing Harm in Possum Control Operations and Experiments in New Zealand

Pest control operations andexperimentation on sentient animals such as thebrushtail possum can cause unnecessary andavoidable suffering in the animal subjects.Minimizing animal suffering is an animalwelfare goal and can be used as a guide in thedesign and execution of animal experimentationand pest control operations.The public has little sympathy for the possum,which can cause widespread environmentaldamage, but does believe that control should beas painless as possible. Trapping and poisoningprovide only short-term solutions to the possumproblem and often involve methods that causesuffering. Intrusive experiments connected withthese methods of control and published in thelast 6 years are reviewed. Many of theexperiments do not attain the welfare standardsrequired by members of the public.Possums also act as vectors for bovinetuberculosis. While this is not as important inthe minds of the public as environmentaldegradation, as long as people wish to continueraising cattle, this disease needs to becontrolled.Immunocontraception is a humane means ofcontrolling possums with wide publicacceptance. The use of vaccines for cows and/orpossums would also cause far less sufferingthan present eradication operations. Researchinto these methods does require some intrusiveexperimentation. This can be reduced if liveanimals are not used for secondary antibodyharvesting, if adequate analgesia is provided,and if potential vaccines or contraceptives aretested under conditions that would beexperienced in the field.     

Forest Integrity at Anthropogenic Edges: Air Pollution Disrupts Bioindicators

The response of corticolous lichens, bryophytes, and vascular plants to anthropogenic edges in northern hardwood forest preserves is compared in east-coast and mid-west (NW Minnesota) sites, using micro-epiphytes on red oak (Quercus rubra) and sugar maple (Acer saccharum). The drastically attenuated lichen flora in the east, apparently due to regional air pollution, restricts the usefulness of these bioindicators, even 120 km from New York City. The forest edge is not necessarily equated with increased light. Established edges may have pronounced shoot growth that shades epiphytes. In the absence of air pollution, lichen and bryophyte species exhibit individual responses to light, humidity, and substrate chemistry. Thus summary variables such as total cover or species richness have limited value as bioindicators of forest integrity.