Protect Krill to Protect Whales
We previously wrote about the importance of krill (marine invertebrates) for supporting oceanic ecosystems. This paper (sub) compared the movement of humpback whales (Megaptera novaeangiliae) to tonnage of krill harvested around the West Antarctic peninsula. The authors found a correlation between spatial areas where the whales spent the most time and high krill harvest. Foraging is energetically expensive for humpbacks, thus it makes sense to hunt in areas with high krill productivity. Of course, fishing is expensive too; thus it is not surprising that whales and humans are competing for the same resources in the same areas. Since the authors evaluated whale behavior and krill fisheries at the management unit scale, this paper has important conservation implications for setting harvest limits at a fine spatial scale.
Side photo of a humpback whale by David Fleetham via ARKive.
Translocating Functional Alleles
Moving individuals between isolated populations is one conservation strategy to increase genetic diversity, especially when a population shows signs of declining fitness due to inbreeding. In 1973, two populations of South Island robins (Petroica australis) were established on two different islands each from five individuals. Over time the populations grew but also inbred. In 2008, female birds from each island population were translocated to the other island. Researchers previously measured an increase in neutral genetic diversity, and this paper follows up by estimating diversity in toll-like receptors and the major histocompatability complex. These loci are in several functional genes associated with immune function. The authors observed that the translocated individuals increased allelic diversity in the population in these functional genes. However, the authors note that some high frequency alleles were shared between the populations, thus any individual offspring could have decreased genetic diversity. They also observed that population specific rare alleles stayed as such, due to a lower probability of translocation. Thus one of the implications of this functional genetic diversity survey is that genotyping pre-translocation may be needed to achieve certain conservation objectives.