Protected species use of a coastal marine migratory corridor connecting marine protected areas

The establishment of protected corridors linking the breeding and foraging grounds of many migratory species remains deficient, particularly in the world's oceans. For example, Australia has recently established a network of Commonwealth Marine Reserves, supplementing existing State reserves, to protect a wide range of resident and migratory marine species; however, the routes used by mobile species to access these sites are often unknown. The flatback marine turtle (Natator depressus) is endemic to the continental shelf of Australia, yet information is not available about how this species uses the marine area. We used a geospatial approach to delineate a coastal corridor from 73 adult female flatback postnesting migratory tracks from four rookeries along the north-west coast of Australia. A core corridor of 1,150 km length and 30,800 km2 area was defined, of which 52 % fell within 11 reserves, leaving 48 % (of equivalent size to several Commonwealth Reserves) of the corridor outside of the reserve network. Despite limited data being available for other marine wildlife in this region, humpback whale migratory tracks overlapped with 96 % of the core corridor, while the tracks of three other species overlapped by 5-10 % (blue whales, olive ridley turtles, whale sharks). The overlap in the distribution ranges of at least 20 other marine vertebrates (dugong, cetaceans, marine turtles, sea snakes, crocodiles, sharks) with the corridor also imply potential use. In conclusion, this study provides valuable information towards proposing new locations requiring protection, as well as identifying high-priority network linkages between existing marine protected areas. © 2014 Springer-Verlag Berlin Heidelberg.

Ecology of fish inhabiting the inter-tidal zone of Swan Bay, Victoria, Australia

Swan Bay is a shallow marine embayment of Port Phillip Bay, just north of Queenscliff, Victoria. It has been part of the Harold Holt Marine Reserves since 1977 and is a seagrass habitat. This study investigated the species of fish present in the inter-tidal zone of Swan Bay, collected information on their ecology, investigated the importance of Swan Bay compared to Port Phillip Bay as a nursery and/or breeding area and compared these results with those of similar seagrsss habitats. Field work was carried out monthly over a two year period, from April 1981 to April 1983, using beach seine nets at Swan Bay and Portarlington. Forty four species of fish were identified from Swan Bay and nineteen from Portarlington. Fish were most abundant during the summer and autumn months when seagrass growth was at a maximum and least abundant during winter due to the absence of seasonal residents and decreased numbers of permanent residents. Swan Bay was found to be an important nursery ground for two commercially-caught species: the Yellow-eye Mullet and the King George Whiting. Juvenile Yellow-eye Mullet were more numerous in Swan Bay than at Portarlington. Smell juvenile King George Whiting were more abundant at Portarlington than in Swan Bay where older juveniles were more numerous. The fish fauna of Swan Bay was found to be similar to western Port but the abundance of species varied. Atherinosome microstoma was the dominant species in terms of abundance and biomass. Diet was found to be different from that reported by Robertson (1979) at Western Port due to the different range of prey items.

Foraging trip strategies and habitat use during late pup rearing by lactating Australian fur seals

Australian fur seals (Arctocephalus pusillus doriferus) are the most conspicuous and abundant marine mammal in shelf waters of south-eastern Australia. To successfully rear offspring, the females must encounter sufficient prey on each foraging trip out of a central place for periods up to11 months each year. We investigated foraging trip strategies and habitat use by the females in three winter–spring periods, 2001–03, from four colonies that span the species’ latitudinal range and contribute 80% of pup production. Trip durations of 37 females averaged 6.1±0.5 (s.e.) days, although >90% of the seal’s time at sea was spent <150 km travel (<2 days) away. Most females exhibited strong fidelities to individually preferred hotspots Females from colonies adjacent to productive shelf-edge waters generally had shorter trips, had smaller ranges, foraged closer to colonies and exhibited less diversity in trip strategies than did those from colonies more distant from a shelf-edge. From a management perspective, there was minimal overlap (<1%) between where females foraged and a system of marine reserves established in 2007, suggesting that habitats visited by lactating Australian fur seals currently receive minimal legislative protection

Subjective risk assessment for planning conservation projects

Conservation projects occur under many types of uncertainty. Where this uncertainty can affect achievement of a project's objectives, there is risk. Understanding risks to project success should influence a range of strategic and tactical decisions in conservation, and yet, formal risk assessment rarely features in the guidance or practice of conservation planning. We describe how subjective risk analysis tools can be framed to facilitate the rapid identification and assessment of risks to conservation projects, and how this information should influence conservation planning. Our approach is illustrated with an assessment of risks to conservation success as part of a conservation plan for the work of The Nature Conservancy in northern Australia. Risks can be both internal and external to a project, and occur across environmental, social, economic and political systems. Based on the relative importance of a risk and the level of certainty in its assessment we propose a series of appropriate, project level responses including research, monitoring, and active amelioration. Explicit identification, prioritization, and where possible, management of risks are important elements of using conservation resources in an informed and accountable manner

Examining the functional role of current area closures used for the conservation of an overexploited and highly mobile fishery species

Protecting essential habitats through the implementation of area closures has been recognized as a useful management tool for rebuilding overfished populations and minimizing habitat degradation. School shark (Galeorhinus galeus) have suffered significant stock declines in Australia; however, recent stock assessments suggest the population may have stabilized and the protection of closed nursery areas has been identified as a key management strategy to rebuilding their numbers. Young-of-The-year (YOY) and juvenile G. galeus were acoustically tagged and monitored to determine ontogenetic differences in residency and seasonal use of an important protected nursery area (Shark Refuge Area or SRA) in southeastern Tasmania. BothYOYand juvenile G. galeus showed a distinct seasonal pattern of occurrence in the SRAwith most departing the area during winter and only a small proportion of YOY (33%) and no juveniles returning the following spring, suggesting areas outside the SRA may also be important during these early life-history stages. While these behaviors confirm SRAs continue to function as essential habitat during G. galeus early life history, evidence of YOY and juveniles emigrating from these areas within their first 1-2 years and the fact that few YOY return suggest that these areas may only afford protection for a more limited amount of time than previously thought. Determining the importance of neighbouring coastal waters and maintaining the use of traditional fisheries management tools are therefore required to ensure effective conservation of G. galeus during early life history.

Community-based monitoring of Victoria´s marine national parks and marine sanctuaries

This study investigated community-based monitoring in Victoria’s Marine National Parks (MNPs) and Sanctuaries (MSs) from January to May 2004. The primary aim of this study was to evaluate the potential for community-based monitoring projects to assist in the collection of data for the management of Victoria’s MNPs and MSs. The pilot habitats that were assessed included subtidal reefs at the Merri MS, intertidal reefs at Ricketts Point MS and seagrass beds at Corner Inlet MNP. The three main objectives for this study were to:
 - Develop a template for the monitoring of marine habitats by community groups.
 - Assess the quality and integrity of data collected by community volunteers.
 - Determine a sustainable model for community monitoring of marine habitats.
Three standard operating procedures (SOPs) in the form of a “how to” manual, were developed for each habitat type. The SOPs were adapted from scientifically robust studies and developed in consultation with community volunteer groups by means of field trials. Volunteer feedback assisted in the final SOP design. The SOP will allow Parks Victoria Rangers to develop community-based programs within the parks. The SOPs are accessible as Parks Victoria Technical Series Numbers 16, 17 and 18. Data collected by volunteers across the three habitat sites were assessed and compared to that collected by scientists. It was found that data quality collected by volunteers was dependent on habitat type and the type of measurement the volunteer was required to assess. Volunteer estimation measurements were highly variable across all three habitat sites, compared to quantitative data collection. Subtidal monitoring had the greatest potential for inconsistency in data collection. Intertidal monitoring is the most sustainable of the three habitat monitoring procedures. Sustainability of community-based monitoring programs is dependent on continued support and training by the management authority of Victoria’s MNPs and MSs. For the expansion of the monitoring programs to other MNPs and MSs, the management authority could expand strong relationships with the community volunteer groups.

Individual variability in Diel Vertical migration of a marine copepod : why some individuals remain at depth when others migrate

The diel vertical migration (DVM) of the copepod Metridia pacifica was examined in Dabob Bay (47°45.05′N, 122°49.71′W), a fjord in Washington state. Although the population showed deep daytime residence (75-175 m), a proportion of the population was found in the surface waters at night. For individuals that migrated to the surface, the mean size of the oil sac was much smaller than those that remained at depth (mean lengths of oil sac 0.25 mm for individuals collected between 0 and 25 m at night, compared with 0.43 mm for individuals from between 125 and 175 m). Similarly, the C : N ratio was lower for animals collected from near the surface, indicative of their lower lipid reserves. These results suggest that individual variability in DVM was influenced by body condition, with those animals with larger lipid stores not needing to risk coming to the surface to feed at night.

Accounting for habitat and seafloor structure characteristics on southern rock lobster (Jasus edwardsii) assessment in a small marine reserve

Where to place marine protected areas (MPAs) and how much area they should cover are some of the most basic questions when designing MPAs. Based on the theory of island biogeography, larger reserves are likely to protect more species and individuals but smaller reserves have been shown to positively influence populations. In this study, we assess a localised population of the ecologically and economically important southern rock lobster (Jasus edwardsii) inside and outside a small reserve. We used standardised fishery assessment trapping methods to sample J. edwardsii populations inside a reserve and an adjacent area outside the reserve. The population characteristics of the captured individuals were compared inside and outside the reserve using t tests (male size, female size,number of reproductive females, number of individuals and biomass), and we found that there were significantly greater numbers and larger individuals and biomass inside the reserve. However, many assessments of MPA effectiveness are confounded by differences in habitat. To account for possible differences in habitat, we collected multibeam bathymetry data to allow us to characterise seafloor structure and video data to assign each sampling location to a biotope class based on macroalgae assemblages. Then, using generalised linear models (GLMs), we assessed differences in populations while accounting for habitat. The GLMs revealed that there was still a significant difference in populations inside the reserve despite habitat differences inside and outside the reserve. We demonstrate a methodological approach to provide a baseline data set to assess MPA effectiveness through time and measure how habitat may respond to indirect consequences of fishing or other human impacts at the species or ecosystem level. We also highlight some of the limitations in sampling design and data availability common in MPA studies and resulting implications for assessment.