Solitary Islands Research Articles

Some anemonefish lack personality: a comparative assessment of behavioral variation and repeatability in relation to environmental and social factors

Determining the extent of repeatable differences in the behavior of animals and the factors that influence behavioral expression is important for understanding individual fitness and population processes, thereby aiding in species conservation. However, little is known about the causes of variation in the repeatability of behavioral differences among species because rarely have comparative studies been undertaken to examine the repeatability of behavioral differences among individuals within their natural ecological settings. Using two species of endemic subtropical anemonefishes, Amphiprion mccullochi and A. latezonatus at Lord Howe and North Solitary Islands, Australia, we conducted an in situ comparative analysis of personality traits, examining the repeatability of boldness, sociability and aggression as well as the potential role of environmental and social factors on behavioral expression. For A. mccullochi, only boldness and aggression were highly repeatable and these behaviors formed a behavioral syndrome. For A. latezonatus, none of the three behaviors were repeatable due to low-inter-individual variation in behavior. We suggest that the harsher and more variable environmental and social conditions experienced by A. latezonatus have resulted in reduced repeatability in behavior, in contrast to A. mccullochi which typically inhabits a more stable lagoonal reef environment. Additionally, group size and size rank, rather than nearest-neighbor distance and anemone size, influenced the expression of these behaviors in both species, suggesting that behavioral variation was more sensitive to social than environmental factors. Overall, differences in repeatability between these closely related species likely reflect adaptations to contrasting environmental and social conditions, although alternative explanations must be considered. The differences in behavioral consistency between these two endemic anemonefishes could lead to disparity in their resilience to environmental or social change in the future.

Cyphastrea salae, a new species of hard coral from Lord Howe Island, Australia (Scleractinia, Merulinidae).

A new zooxanthellate reef-dwelling scleractinian coral species, Cyphastrea salae sp. n. (Scleractinia, Merulinidae), is described from Lord Howe Island Australia. The new species can be distinguished morphologically from the only other congeneric species on Lord Howe Island, C. microphthalma, by the number of primary septa (12 vs. 10) and the much taller corallites (mean ± SE: 1.0 ± 0.07 mm v 0.4 ± 0.04 mm). The relationship of C. salae to four of the other eleven currently accepted species in the genus was explored through analyses of nuclear (28S rDNA) and mitochondrial (noncoding intergenic region) gene sequences. Cyphastrea salae sp. n. forms a strongly supported clade that is distinct from a clade containing three species found commonly in Australia, C. chalcidicum, C. serailia, and C. microphthalma. One specimen was also found in the Solitary Islands, another high latitude location in south-eastern Australia. The discovery of a new species in the genus Cyphastrea on high latitude reefs in south-eastern Australia suggests that other new species might be found among more diverse genera represented here and that the scleractinian fauna of these isolated locations is more distinct than previously recognised.

A moray’s many knots: knot tying behaviour around bait in two species of Gymnothorax moray eel

Being able to tie their body into a knot is beneficial to some moray eels and other cylindrical vertebrates for various reasons, although not all morays’ tie knots. Knot tying can generate leverage for feeding activity by moving the knot up the body, and this leverage may be affected by knot type. Three types of knots are known to have been used by morays’ and this study further elucidates this behaviour and ability. Baited Remote Underwater Videos (BRUVs) were used to compare knot tying between the moray eels Gymnothorax prasinus and Gymnothorax prionodon in the Solitary Islands region, eastern Australia. Gymnothorax prasinus tied more knots overall and more types of knot than G. prionodon (five types vs one type, respectively). Both tied the overhand knot and this was the most common knot used by G. prasinus. The figure of eight knot was used two times more than the double overhand knot, being relatively wider and likely easier to move up the body. Gymnothorax prasinus also tied two undescribed knots, now called the ‘moray knot’ and the ‘morays banana knot’, which have more crossings and are bulkier, increasing potential for generating leverage. However, their uncommon use indicates costs may outweigh benefits of these more complex knots. Lower habitat complexity in deeper waters may influence differences in knot tying as G. prasinus were only recorded shallower than 40 m and G. prionodon mainly deeper. These findings further reveal the utility and complexity of knot tying in moray species and cylindrical vertebrates generally.

Slaughterhouse report of intrahepatic cholangiocarcinoma in a Holstein cow

Cholangiocarcinoma (CCA) is a primary tumor of the bile duct epithelium. Cholangiocarcinoma is relatively uncommon in domestic animals and the previous reports are documented more in dogs and cats, and less in other species. The current study described intrahepatic CCA in a 6-year-old female Holstein cow. Grossly, multiple parenchyma were scattered throughout the liver parenchyma. Histopathologically, the tumoral masses were composed of gland-like, tubular, acinar structures or solitary islands that embedded in the abundant connective tissue stroma with a cuboidal to columnar epithelial cells. Polymorphism and mitotic figures were present. In considering to the histopathologic characteristics, a diagnosis of cholangiocarcinoma was made. Predisposing factors for this neoplasm have not been identified. More studies require for understanding the mechanisms and risk factors of CCA occurrence.

Integrating Seafloor Habitat Mapping and Fish Assemblage Patterns Improves Spatial Management Planning in a Marine Park

ABSTRACT Malcolm, H.A., Jordan, A., Schultz, A.L., Smith, S.D.A., Ingleton, T., Foulsham, E., Linklater, M., Davies, P., Ferrari, R., Hill, N., and Lucieer, V., 2016. Integrating seafloor habitat mapping and fish assemblage patterns improves spatial management planning in a marine park. In: Vila-Concejo, A.; Bruce, E.; Kennedy, D.M., and McCarroll, R.J. (eds.), Proceedings of the 14th International Coastal Symposium (Sydney, Australia). Journal of Coastal Research, Special Issue, No. 75, pp. 1292 - 1296. Coconut Creek (Florida), ISSN 0749-0208. Marine Protected Areas (MPAs) are important spatial mechanisms for managing human activities, if effectively planned. The Solitary Islands Marine Park (SIMP), covering 720 km2 of coastal waters in New South Wales, Australia, includes reef and unconsolidated habitats up to 17 km from shore and 75 m depth. When established in 1991, there was limited knowledge of biotic patterns, seafloor habitats and habitat-biotic relationships in the multiple-use SIMP, which constr...

Subtropical anemonefish Amphiprion latezonatus recorded in two additional host sea anemone species

Anemonefishes are habitat specialists that form obligate symbioses with host sea anemones (Fautin and Allen 1997). Some anemonefishes associate with a range of hosts, whereas others only use one host species. The wideband anemonefish Amphiprion latezonatus is endemic to high-latitude reefs in eastern Australian and, in published sources, has previously only been documented with Heteractis crispa (Fautin and Allen 1997; Ollerton et al. 2007). Here, we establish that A. latezonatus utilizes two additional species, Entacmaea quadricolor and Stichodactyla gigantea. In an unpublished thesis, Richardson (1996) recorded A. latezonatus associating with E. quadricolor in the Solitary Islands Marine Park, New South Wales (NSW), Australia. Sub-adults were found to occupy both H. crispa and E. quadricolor, while breeding pairs were found only in E. quadricolor (Richardson 1996). Our observations confirm the use of these hosts at this location, but also indicate that

Distinct cross-shelf gradient in mesophotic reef fish assemblages in subtropical eastern Australia

The hypothesized importance of mesophotic (30 to 150 m depth) reefs justifies the recent trend in scientific scrutiny of these systems. However, to enable assessment of complex concepts such as connectivity and reef dynamics, baseline assemblage characteristics must first be established. This study used baited remote underwater video (BRUV) technology to investigate the assemblage structure of predatory and scavenging fishes across 4 mesophotic reef bands at ca. 30 to 82 m depth, at 2 locations 25 km apart in subtropical eastern Australia. We aimed to quantify patterns in predatory and scavenging fish assemblage structure at these reefs across the continen- tal shelf and relate this to putative structuring environmental variables. Strong cross-shelf gradi- ents were identified in species richness and overall assemblage composition. While the pattern of latitudinal affiliation did not change across the shelf, predatory and scavenging fish assemblages at non-adjacent reefs were statistically distinct (PERMANOVA interaction term p = 0.012), and best (but not well) explained by depth alone (BIOENV ρ = 0.396). A high proportion (15 to 45%) of the fish species at each reef band were found only within that band. These cross-shelf trends con- trasted with those described from more complex shelf topography such as at the Solitary Islands (250 km south), and did not match published patterns of epibenthic assemblage structure. Our results highlight the need for detailed information on mesophotic reef assemblage structure to support marine conservation and reserve design initiatives, rather than relying on generalised trends from the literature.

Sediment variability affects fish community structure in unconsolidated habitats of a subtropical marine park

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 532:213-226 (2015) - DOI: https://doi.org/10.3354/meps11311 Sediment variability affects fish community structure in unconsolidated habitats of a subtropical marine park Arthur L. Schultz1,2,*, Hamish A. Malcolm3, Michelle Linklater4, Alan R. Jordan5, Tim Ingleton4, Stephen D. A. Smith1,2 1National Marine Science Centre, Southern Cross University, Charlesworth Bay, Coffs Harbour, NSW 2450, Australia 2Marine Ecology Research Centre, School of Environment, Science and Engineering, Southern Cross University, Lismore, NSW 2480, Australia 3Marine Ecosystem Research, Fisheries NSW, Department of Primary Industries, Coffs Harbour, NSW 2450, Australia 4New South Wales Office of Environment and Heritage, 59 Goulburn St, Sydney, NSW 2000, Australia 5New South Wales Department of Primary Industries, Locked Bag 1, Port Stephens, NSW 2315, Australia *Corresponding author: a.schultz.22@student.scu.edu.au ABSTRACT: Unconsolidated sediments form extensive seafloor habitats worldwide, yet few studies have examined fish assemblage patterns in relation to specific sediment type or morphology. Baited remote underwater videos (BRUVs) were deployed at 3 sites (3 replicates per site) in the Solitary Islands Marine Park (SIMP), in each of 4 apparent ‘habitat types’ identified from swath acoustic mapping backscatter imagery and bathymetry. Habitat types ranged in reflected signal backscatter intensity: very dark, dark, light, very light. Additionally, apparent morphological features were associated with each (e.g. very dark = lens-shaped; light = sand waves). Sediments were characterised at each site by conducting granulometric analyses of samples collected using a van Veen grab. Both the darker ‘habitat types’ were found to be gravels and both lighter types were fine sands. There was a strong pattern in fish assemblage structure in relation to habitat type, and distinct assemblages were seen between ‘gravel’ and ‘fine sand’ habitats. Species richness was higher in gravel than in sand habitats. Additionally, 6 species were only recorded in the very dark lens habitat. However, there were no apparent differences in assemblage patterns between the 2 fine sand habitats. Of the different granulometric measures, fish assemblages were most strongly correlated with a combination of median grain size, % gravel and arithmetic sorting. The current habitat classification system for the SIMP includes habitat type (unconsolidated or hard substrata) as criteria for conservation planning. Further division of unconsolidated habitats into ‘gravel’ and ‘fine sand’ categories is needed to better represent biotic assemblages. KEY WORDS: Fish assemblage · Sediment type · Granulometrics · Backscatter intensity · Marine protected area Full text in pdf format PreviousNextCite this article as: Schultz AL, Malcolm HA, Linklater M, Jordan AR, Ingleton T, Smith SDA (2015) Sediment variability affects fish community structure in unconsolidated habitats of a subtropical marine park. Mar Ecol Prog Ser 532:213-226. https://doi.org/10.3354/meps11311 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 532. Online publication date: July 21, 2015 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2015 Inter-Research.

Decadal Changes in the Abundance and Length of Snapper (Chrysophrys auratus) in Subtropical Marine Sanctuaries.

Abundance and length of the highly-targeted snapper Chysophrys auratus were compared between sites in 'no take' areas (Sanctuary Zones: SZ), partial protected areas which are fished (Habitat Protection Zones: HPZ), and areas outside (Outside) the Solitary Islands Marine Park (SIMP), Australia. Baited Remote Underwater Video (BRUV) sampling on shallow rocky reef (15 - 25 m) was conducted annually from 2002 until 2014 in the Austral-winter, covering the decade after these marine park zones were established (2002). Additional deeper sites (25 - 40 m) were sampled in 2010-2011 to assess if findings were more-broadly applicable. Lengths were measured using stereo-BRUVs from 2011-2014. Snapper were significantly more abundant in SZ overall and in most years compared with the other two management types, which did not significantly differ. Snapper rapidly increased after 2 - 3 years protection in all management types, especially SZ. Snapper were present on more SZ deployments than HPZ and Outside after the same period. The positive SZ response in snapper abundance on shallower reef was also found at a broader spatial scale on deeper sites. Again the two fished management types did not show significant differences among each other. There was considerable variation in snapper abundance between years, with strong peaks in 2005, 2009 and 2014 especially in SZ. Abundances remained higher in SZ in the year or two following a strong peak, but decreased to similar abundances to fished areas before the next peak. Snapper length frequency distribution significantly differed between SZ and both fished management types, with more larger snapper within SZ including a higher proportion (58%) that were legal-sized (>25.7 cm FL). HPZ and Outside did not significantly differ from each other, and were dominated by individuals below legal size. Overall, SZ's have positively influenced abundance and length of snapper on these subtropical rocky reefs.

Diverse associations among coral host haplotypes and algal endosymbionts may drive adaptation at geographically peripheral and ecologically marginal locations

AbstractAimTo understand the evolutionary history and local adaptation of marginal, subtropical populations of a common reef‐building coral (genus Pocillopora) and their Symbiodinium endosymbionts.LocationSubtropical coastal (Solitary Islands, Flinders Reef) and offshore (Lord Howe Island, Middleton Reef, Elizabeth Reef) eastern Australia and the southern Great Barrier Reef (GBR).MethodsCoral genetic diversity and identity were assessed by sequence analysis of a mitochondrial (mtDNA) region (ORF), a PCR‐based mtDNA screening assay, and microsatellite loci. The identity of the Symbiodinium was determined using denaturing gradient gel electrophoresis (DGGE) analysis of nuclear rDNA ITS2.ResultsThe mitochondrial haplotype Pocillopora damicornis Type α was present at all locations: 100% on the GBR and Flinders Reef, 85% and 87% respectively at Middleton Reef and Elizabeth Reef, 25% at Lord Howe Island and 5% at the Solitary Islands. An additional haplotype was observed at the Solitary Islands (corresponding to the recently described Pocillopora aliciae), and a third haplotype at the offshore high‐latitude reefs (termed the Lord Howe Island haplotype). Congruent with the mtDNA results, microsatellite markers showed the same three population clusters. One Symbiodinium profile occurred in 100% of the samples at two of the three GBR reefs and Flinders Reef, and a different profile occurred in all colonies analysed from Lord Howe Island. These two profiles were observed at Middleton and Elizabeth reefs in association with both P. damicornis Type α and the Lord Howe Island coral haplotype. Two unique Symbiodinium profiles were detected at the Solitary Islands.Main conclusionsWe detected evidence for local adaptation of subtropical coral and Symbiodinium, flexible coral–Symbiodinium associations, and the presence of transition zones that may contain evolutionarily significant novelty.

Levels of intervention – reducing SCUBA-diver impact within subtropical marine protected areas

Subtropical rocky reefs are ecotonal habitats that support unique biodiversity and attract all levels of self-contained underwater breathing apparatus (SCUBA) divers. Compared to tropical coral reefs, there have been few studies evaluating the effects of SCUBA diving on these communities. Cape Byron and Solitary Islands marine parks in northern New South Wales include some of the most intensively dived sites in Australia, outside of the Great Barrier Reef. Most of those diving sites are located within management zones that offer the highest level of protection. Contact by divers, or their equipment, is a principal mechanism for chronic impact on benthic life forms. This study tested two levels of intervention over the standard dive briefing to determine their effectiveness for reducing SCUBA-diver contact: (1) targeted pre-dive briefing with specific reference to minimising benthic contact; and (2) direct underwater reinforcement at the time of first contact. Both intervention levels significantly reduced the number of contacts made by divers. The targeted briefing is the easiest and most cost effective to implement and is the least intrusive on the diving experience. The more intensive approach of underwater intervention may be required in more sensitive areas, or for those divers who have been shown to create the majority of damage.

Range extensions for heterobranch sea slugs (formerly opisthobranch) belonging to the families Diaphanidae, Plakobranchidae and Facelinidae on the eastern coast of Australia – CORRIGENDUM

Southern range extensions of the tropical Australian heterobranch sea slug fauna may be symptomatic of climate change, particularly in south-eastern Australia, a recognized climate change hot-spot. In the Solitary Islands Marine Park, northern New South Wales, the presence of biogeographic mixing means that the southern coastal distribution limit of several tropical marine species and the northern limit of some temperate species overlap. During a year-long series of monthly surveys of sea slug communities on intertidal rocky shores, we observed four species beyond their previously recorded range – Colpodaspis thompsoni, Elysia pusilla, Phidiana bourailli and Herviella claror. The southern migration of species is an anticipated response to warming seas and we note an apparent extension of the southern limit for these taxa.

Range extensions for heterobranch sea slugs (formerly opisthobranch) belonging to the families Diaphanidae, Plakobranchidae and Facelinidae on the eastern coast of Australia

Southern range extensions of the tropical Australian heterobranch sea slug fauna may be symptomatic of climate change, particularly in south-eastern Australia, a recognized climate change hot-spot. In the Solitary Islands Marine Park, northern New South Wales, the presence of biogeographic mixing means that the southern coastal distribution limit of several tropical marine species and the northern limit of some temperate species overlap. During a year-long series of monthly surveys of sea slug communities on intertidal rocky shores, we observed four species beyond their previously recorded range –Colpodaspis thompsoni, Elysia pusilla, Phidiana bourailliandHerviella claror. The southern migration of species is an anticipated response to warming seas and we note an apparent extension of the southern limit for these taxa.

Long-term effects of marine park zoning on giant mud crab Scylla serrata populations in three Australian estuaries

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 508:163-176 (2014) - DOI: https://doi.org/10.3354/meps10865 Long-term effects of marine park zoning on giant mud crab Scylla serrata populations in three Australian estuaries Paul A. Butcher1,4,*, Andrew J. Boulton1, William G. Macbeth2, Hamish A. Malcolm3 1School of Rural and Environmental Science and the National Marine Science Centre, University of New England, Coffs Harbour, New South Wales 2450, Australia 2Cardno Ecology Lab, Cardno NSW/ACT, PO Box 19, St Leonards, New South Wales 1590, Australia 3New South Wales Department of Primary Industries, PO Box 4297, Coffs Harbour, New South Wales 2450, Australia 4Present address: New South Wales Department of Primary Industries, National Marine Science Centre, PO Box 4321, Coffs Harbour, New South Wales 2450, Australia *Corresponding author: paul.butcher@dpi.nsw.gov.au ABSTRACT: Multiple-use marine parks are a powerful management tool to help protect marine biodiversity and sustain wild fisheries while allowing some access to recreational and commercial activities using zoning arrangements. Research has focused on fish but far less is known about the effectiveness of zoning for other groups, such as exploited crustaceans, especially in estuaries. In this 8 yr study, we tested the hypotheses that unfished zones, which had been closed to fishing since 1991, would have higher abundances (catch per unit effort) of the giant mud crab Scylla serrata in 3 estuaries (Wooli, Corindi and Sandon) of the Solitary Islands Marine Park (SIMP) in New South Wales, Australia, and that recovery after fishing closure would be rapid. Replicate fished and unfished zones were sampled from December 1998 (Wooli) and July 2000 (Corindi and Sandon) until April 2007. In August 2002, re-zoning occurred with some estuarine sections re-opened to trapping, some newly closed and others either remaining closed or open. This enabled Before-After-Control-Impact analyses to test our hypotheses. Crab numbers increased rapidly after zone closure and unfished zones protected giant mud crabs from exploitation with catches 2 to 3 times greater than in fished zones. Although there was substantial temporal variation in crab abundance within and among the 3 estuaries, responses to zoning were consistent and spatial protection in estuaries in the SIMP proved effective for sustaining giant mud crab populations. This type of management shows promise for protecting or replenishing stocks of other species of crabs worldwide. KEY WORDS: Marine parks · Giant mud crab · Scylla serrata · No-take zones · CPUE Full text in pdf format PreviousNextCite this article as: Butcher PA, Boulton AJ, Macbeth WG, Malcolm HA (2014) Long-term effects of marine park zoning on giant mud crab Scylla serrata populations in three Australian estuaries. Mar Ecol Prog Ser 508:163-176. https://doi.org/10.3354/meps10865 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 508. Online publication date: August 04, 2014 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2014 Inter-Research.

Depth and medium-scale spatial processes influence fish assemblage structure of unconsolidated habitats in a subtropical marine park.

Where biological datasets are spatially limited, abiotic surrogates have been advocated to inform objective planning for Marine Protected Areas. However, this approach assumes close correlation between abiotic and biotic patterns. The Solitary Islands Marine Park, northern NSW, Australia, currently uses a habitat classification system (HCS) to assist with planning, but this is based only on data for reefs. We used Baited Remote Underwater Videos (BRUVs) to survey fish assemblages of unconsolidated substrata at different depths, distances from shore, and across an along-shore spatial scale of 10 s of km (2 transects) to examine how well the HCS works for this dominant habitat. We used multivariate regression modelling to examine the importance of these, and other environmental factors (backscatter intensity, fine-scale bathymetric variation and rugosity), in structuring fish assemblages. There were significant differences in fish assemblages across depths, distance from shore, and over the medium spatial scale of the study: together, these factors generated the optimum model in multivariate regression. However, marginal tests suggested that backscatter intensity, which itself is a surrogate for sediment type and hardness, might also influence fish assemblages and needs further investigation. Species richness was significantly different across all factors: however, total MaxN only differed significantly between locations. This study demonstrates that the pre-existing abiotic HCS only partially represents the range of fish assemblages of unconsolidated habitats in the region.

Social and economic effects of spatial distribution in island communities: Comparing the Isles of Scilly and Isle of Wight, UK

There has been increasing awareness that communities based on islands are subject to particular island-related factors (the so-called ‘island effect’). This paper sheds empirical light on how the island effect differs in different kinds of island communities, specifically solitary islands on the one hand and archipelagos on the other. It does so by comparing two subnational island jurisdictions (SNIJs) in England: the Isles of Scilly and the Isle of Wight. By analysing census statistics, we show how the spatial distribution in the Isles of Scilly (an archipelago) and the Isle of Wight (a solitary island) is interrelated with patterns of population and employment. Although the Isles of Scilly and the Isle of Wight are both tourism economies, the data indicates that, in social and economic terms, the Isles of Scilly benefits while the Isle of Wight suffers as a result of their different patterns of spatial distribution. We conclude that an island community’s spatial distribution has a significant influence on its societal development and that the island effect differs among islands with different patterns of spatial distribution.

Impacts of Climate-Change-Driven Sea Level Rise on Intertidal Rocky Reef Habitats Will Be Variable and Site Specific

Intertidal rocky reefs are complex and rich ecosystems that are vulnerable to even the smallest fluctuations in sea level. We modelled habitat loss associated with sea level rise for intertidal rocky reefs using GIS, high-resolution digital imagery, and LIDAR technology at fine-scale resolution (0.1 m per pixel). We used projected sea levels of +0.3 m, +0.5 m and +1.0 m above current Mean Low Tide Level (0.4 m). Habitat loss and changes were analysed for each scenario for five headlands in the Solitary Islands Marine Park (SIMP), Australia. The results indicate that changes to habitat extent will be variable across different shores and will not necessarily result in net loss of area for some habitats. In addition, habitat modification will not follow a regular pattern over the projected sea levels. Two of the headlands included in the study currently have the maximum level of protection within the SIMP. However, these headlands are likely to lose much of the habitat known to support biodiverse assemblages and may not continue to be suitable sanctuaries into the future. The fine-scale approach taken in this study thus provides a protocol not only for modelling habitat modification but also for future proofing conservation measures under a scenario of changing sea levels.

Phytoplankton composition under contrasting oceanographic conditions: Upwelling and downwelling (Eastern Australia)

Phytoplankton abundance and distribution along the east coast of Australia are driven primarily by the southward flowing East Australian Current (EAC), which transports tropical water masses to temperate latitudes. The Solitary Islands Marine Park (SIMP, ~30°S) is located north of the EAC separation point (~32°S) in this tropical–temperate transition zone. In this study, we describe the oceanographic context (wind, current and nutrient load) during a wind-driven downwelling and a current-driven upwelling event, both sampled in austral winter only ten days apart. We investigate the effect of these contrasting oceanographic conditions on phytoplankton abundance, composition and distribution along a cross-shelf transect. During downwelling we find a cross-shelf transition in microphytoplankton composition from an offshore- to an inshore-community associated with nutrient gradients (nitrate and silicate). Strong vertical mixing leads to increased occurrences of benthic diatoms in near-shore surface waters. During upwelling conditions, elevated nutrient availability results in maximum microphytoplankton abundances (mainly oceanic diatoms) and increased species richness on the mid-shelf. An increase in dinoflagellates and silicoflagellates (mid-shelf) and the appearance of tropical phytoplankton (especially picoplankton and dinoflagellates, offshore) signals a strong impact of the EAC across all shelf communities. Nanoplankton are a major part of the winter phytoplankton community during both oceanographic regimes (~40–50% of TChl a). Our findings provide evidence of EAC-driven, nutrient-rich, slope water intrusion in the SIMP as expressed by cross-shelf phytoplankton variability. We suggest that rapid (~weekly) changes in phytoplankton composition along the east Australian coast are likely to be enhanced by the climate change-induced warming/strengthening of the EAC.

Distribution, relative abundance and size composition of the threatened serranid Epinephelus daemelii in New South Wales, Australia

The aim of this study was to undertake baseline surveys on the distribution, relative abundance and total lengths (LT ) of a threatened epinephelid species, black cod Epinephelus daemelii, in New South Wales (NSW), Australia, their westernmost distribution. Diving surveys at 83 sites where E. daemelii were expected to occur were undertaken from 2009 to 2011 using 45 min roving diver counts. Sites were spread through northern NSW, including Lord Howe Island (LHI). Individual fish were measured using stereo-video, enabling accurate length measurement. Surveys were repeated at a sub-set of sites to assess temporal variation across days, seasons and years. A total of 117 E. daemelii were recorded during baseline surveys, occurring at 42% of the surveyed sites. Across all surveys, the highest numbers recorded (14-18 individuals at a site) were at the outer Solitary Islands and Fish Rock (Smoky Cape). Fewer E. daemelii were found southwards, but two sites in the Port Stephens-Great Lakes Marine Park had consistent numbers (three to six) over four annual surveys. Only 12 E. daemelii were recorded from eight of the 18 sites at LHI. The numbers observed at re-surveyed sites were generally stable over years. There were latitudinal and cross-shelf differences in LT . Individuals in the north were found to be significantly larger than those further south, and fish offshore were significantly larger than those inshore. The largest measured fish was 135 cm, smaller than the maximum LT (c. 170 cm) recorded for this species. The smallest fish was 26 cm. Overall, it is considered that the abundance of E. daemelii is low compared to anecdotal data even though they have been protected for c. 30 years in NSW. These findings provide an essential benchmark to assess ongoing status and response to protective management.

Pole-ward range expansion of Acropora spp. along the east coast of Australia

[Extract] Global temperature has warmed approximately 0.35 °C over the last 50 years. In response, many tropical species are expanding their ranges pole-ward. For example, a number of tropical fish species have recently established populations in temperate regions along the east coast of Australia, as rises in sea temperatures enable them to survive over winter (Figueria and Booth 2010). Similarly, in Japan, two common tropical Acropora species have been expanding their range pole-ward since the 1930s (Yamano et al. 2011). However, there is no evidence to date of similar changes in the distribution of corals along the east coast of Australia. In December 2011, in the Solitary Islands (30 °S), we observed four coral species that had not been recorded in the previous extensive surveys of scleractinian corals (Harriott et al. 1994 and references therein): Acropora intermedia, A. microclados, A. monticulosa (Fig. 1) and A. gemmifera. These species are well defined morphologically, they are easy to recognise in the field and the colonies observed were all large (Fig. 1). Consequently, they were unlikely to have been overlooked in the previous surveys. Average winter temperatures in the Solitary Islands have increased by approximately 0.5 °C since 1975 (Figueria and Booth 2010), the date of the first coral surveys. These pole-ward range expansions raise the possibility that corals along the east coast of Australia may be in the process of adjusting to changes in the regional environment caused by global warming.