Rohan J. C. Currey

Unsustainable dolphin-watching tourism in Fiordland, New Zealand.

Bottlenose dolphins are a key resource of the tourism industry in Fiordland and are used on a daily basis by the tour operators offering cruises on the fiords. Recent studies have shown that the current levels of dolphin-boat interactions in this region cannot be sustained by bottlenose dolphins. Interactions have both shortand longterm effects on both individuals and their populations. Population models indicate that these effects may be affecting the viability of the three bottlenose dolphin populations living in Fiordland. We are currently observing drastic changes in the bottlenose dolphin population living in Doubtful Sound which can be linked to the level of boat interactions to which they are currently exposed. The creation of a multi-level marine mammal sanctuary would help minimise dolphin-boat interactions and still allow for some further growth in the tourism sector in Fiordland.

Do parasites affect burrowing depth and habitat choice of sand hoppers, Talorchestia quoyana (Amphipoda: Talitridae)?

Abstract Talorchestia quoyana is the most abundant sand hopper (Amphipoda: Talitridae) on New Zealands beaches. These supralittoral detritivores are host to a parasitic mermithid nematode, Thaumamermis zealandica. In other systems, mermithids have been found to manipulate host behaviour to facilitate the continuation of their lifecycle. The aim of the present study was to determine if the burrowing behaviour of T. quoyana showed evidence of manipulation by T. zealandica. Two studies were conducted to assess the spatial and temporal patterns in sand hopper burrowing under field and laboratory conditions. Sand hopper burrowing behaviour showed considerable variation, related to sand hopper length, sand hopper distribution, month of collection, and experimental moisture conditions. The presence of parasites was not a significant factor in determining sand hopper burrowing behaviour, a result contrary to previous laboratory findings for this system. This study illustrates the benefits of combining both field and laboratory experiments to evaluate whether or not parasites alter host behaviour.

Do parasites affect burrowing activity and emergence of sand hoppers, Talorchestia quoyana (Amphipoda: Talitridae)?

Sand hoppers (Amphipoda: Talitridae) are semiterrestrial crustaceans that feed upon stranded kelp. Their burrowing behaviour plays an important role in reintroducing nutrients into the sediment. The most abundant sand hopper on New Zealand’s beaches is Talorchestia quoyana Milne-Edwards, 1840. It is host to a parasitic mermithid nematode, Thaumamermis zealandica Poinar, Latham and Poulin, 2002, which invariably kills its sand hopper host by emerging to complete its maturation and reproduction in a moist sand environment. The aim of the present study was to assess if the burrowing behaviour of Ta. quoyana showed pathologic consequences of infection by Th. zealandica. Two experiments were conducted to assess temporal variation in sand hopper burrowing in vitro. Parameters measured included the hour after sunrise and sunset that sand hoppers first emerged and the number of surface visits in the first hour after emergence. Across experiments, sand hopper burrowing behaviour showed considerable heterogeneity r...