Predicting the potential long‐term influence of climate change on vendace (Coregonus albula) habitat in Bassenthwaite Lake,U.K.

1. The long‐term suitability of Bassenthwaite Lake as a habitat for vendace (Coregonus albula) was assessed using two models. The first was the phytoplankton model (PROTECH) that provided temperature and phytoplankton biomass outputs that were used to drive a second model of lake oxygen (LOX). 2. Both temperature and oxygen concentrations were used to define the available habitat for the adult vendace, using 18 °C as an upper and 2 mg L^?1 as a lower threshold, respectively. The outputs of both models were compared with 4 years of observed data for the purposes of validation and produced good simulations of water temperature, total chlorophyll a and oxygen concentrations in the epilimnion, hypolimnion and at the lake bottom. 3. Using the outputs of a regional climate model (RCM) simulating 20 years of both present and future climate conditions for this part of the United Kingdom, both models were re‐run. These data suggest the future climate will cause a mean increase of >2 °C in water temperature, little change in overall phytoplankton biomass and a 10% decline in oxygen concentration. 4. Using the thresholds defined above, the habitat volume will decline greatly under the future climate scenarios, with all of the 20 years simulated having periods of zero habitat volume for >7 consecutive days, primarily caused by high temperature. These results suggest that the long‐term viability of the lake as a habitat for this rare fish is extremely low.     

Contribution of transpiration to forest ambient vapour based on isotopic measurements

Using a simple isotope mixing model, we evaluated the relative proportion of water vapour generated by plant transpiration and by soil evaporation at two sites in the Amazon basin. Sampling was carried out at two different soil covers (forest and pasture), in a seasonal tropical rainforest at eastern Amazon where major deforestation is the result of land-use change, and compared to a less seasonal central Amazon forest. In both forests, vapour from transpiration was responsible for most, if not all, of the water vapour generated in the forest, while it could not be detected above the grassy pastures. Thus the canopy transpiration may be a major source of water vapour to the forest and perhaps to the atmosphere during the dry season. The results are discussed in relation to predictive models based on net radiation that usually are not able to distinguish between transpiration and evaporation.     

Isotopic and genetic evidence for culturally inherited site fidelity to feeding grounds in southern right whales (Eubalaena australis)

Ocean warming will undoubtedly affect the migratory patterns of many marine species, but specific changes can be predicted only where behavioural mechanisms guiding migration are understood. Southern right whales show maternally inherited site fidelity to near-shore winter nursery grounds, but exactly where they feed in summer (collectively and individually) remains mysterious. They consume huge quantities of copepods and krill, and their reproductive rates respond to fluctuations in krill abundance linked to El Niño Southern Oscillation (ENSO). Here we show that genetic and isotopic signatures, analysed together, indicate maternally directed site fidelity to diverse summer feeding grounds for female right whales calving at Península Valdés, Argentina. Isotopic values from 131 skin samples span a broad range (–23.1 to –17.2‰δ¹³C, 6.0 to 13.8‰δ¹⁵N) and are more similar than expected among individuals sharing the same mitochondrial haplotype. This pattern indicates that calves learn summer feeding locations from their mothers, and that the timescale of culturally inherited site fidelity to feeding grounds is at least several generations. Such conservatism would be expected to limit the exploration of new feeding opportunities, and may explain why this population shows increased rates of reproductive failure in years following elevated sea-surface temperature anomalies off South Georgia, the richest known feeding ground for baleen whales in the South Atlantic.     

Isolation and characterization of ten microsatellite loci for Senegal sole (Solea senegalensis Kaup)

Senegal sole (Solea senegalensis Kaup) is a high‐value marine flatfish exploited in both fisheries and aquaculture. Here we describe the isolation of seven tetranucleotide and three dinucleotide polymorphic microsatellite loci. Characteristics of a captive broodstock and a wild population are described. Three loci displayed a significant departure from Hardy–Weinberg expectations in both populations, suggesting a substantial frequency of null alleles. The remaining seven loci were found to be in equilibrium in the wild population, whereas only four of them were in the cultured population. Cross‐species amplification was successful for three loci in other five flatfishes.     

Characterization of microsatellite loci for the redbanded seabream,Pagrus auriga (Teleostei,Sparidae)

The redbanded seabream Pagrus auriga (Teleostei, Sparidae) is a species of a high commercial value in Spain. There is currently little information available about the genetic characteristics of both wild and cultured populations. In this survey, we have developed eight polymorphic microsatellites for the redbanded seabream using an enriched genome library protocol. All of them were polymorphic in the 64 individuals tested, 22 of which were wild specimens, and 42 were individuals from a captive reproductive broodstock. These markers can potentially be useful tools for use in population genetic studies.     

Diving patterns in shags and cormorants (Phalacrocorax): tests of an optimal breathing model

Four species of shags and cormorants were observed while diving for food in estuaries and coastal waters in southwest England and the South Island of New Zealand. Times spent on the surface and under water were recorded. The correlations between dive and surface times were examined between and within bouts of dives. All species showed a positive correlation between the mean dive time and the mean surface time for the bout. Analysis of within-bout correlations, however, showed different patterns between species. For the Shag Phalacrocorax aristotelis, there was a positive relationship within bouts between dive time and the preceding surface time, and correlations between dive time and the succeeding surface time were due only to the autocorrelation of surface times. This anticipatory breathing pattern was predicted by an optimal breathing model proposed by D. L. Kramer. For the Little Shag Phalacrocorax melanoleucus, dive times were significantly correlated within bouts with the following surface time, but correlations with the succeeding surface time were due only to the autocorrelation of surface times. This implies that breathing in this species is reactive rather than anticipatory. The Cormorant Phalacrocorax carbo and the Pied Shag Phalacrocorax varius showed independent within-bout correlations with both preceding and succeeding surface times, implying both anticipatory and reactive breathing. The within-bout dependence of dive time on surface times was weak in all species, suggesting that oxygen is stored from one dive to another to some extent.