A new species of the waspfish genus Ocosia (Teleostei: Tetrarogidae) from the Coral Sea, with a key to species in the genus

The new waspfish Ocosia dorsomaculata n. sp. (Tetrarogidae) is described, based on specimens from Australia (5) and New Caledonia (51). Although O. dorsomaculata and Ocosia apia Poss & Eschmeyer 1975 both share modally XVI, 8 dorsal-fin rays with a long second dorsal-fin spine, and presence of supraocular, lateral lacrimal, and suborbital spines, the former has modally 13 pectoral-fin rays (vs. usually 12 in the latter), a lower modal count of total gill rakers (10 vs. 16–18), greater upper-jaw length, greater third to sixth dorsal-fin spine lengths, the third dorsal-fin spine slightly shorter than the second dorsal-fin spine (vs. third spine markedly shorter than second spine), 1 or 2 prominent pale brown to dark brown blotches on the membrane between the fifth to eighth or sixth to ninth dorsal-fin spines (vs. 1 blotch on the membrane around the third dorsal-fin spine and 1 blotch on the membrane between the sixth to eighth dorsal-fin spines), and body with 11–15 longitudinal pale brown to dark brown bars along lateral line (vs. irregular brown specks). A key to the species of Ocosia is given.

Location, Area, Curvature and Temporal Trends of Coral Sea Tropical Cyclone Tracks, Over 50 Years

Tropical Cyclones (TCs) with genesis in the Coral Sea, often near the east coast of Australia, present significant hazards to coastal regions in their surroundings. There has, therefore, been significant recent efforts to extract information from records of their historical tracks in order to help predict their future behaviour in the light of a changing climate. In this study, the Australian Bureau of Meteorology (BOM) database of TC tracks over the last fifty years were grouped based on K-means clustering of the maximum wind-weighted centroids. Track shape variance and track curvature (sinuosity) were assessed. Three well defined clusters of TC tracks were identified, and the results showed predominant directions of TC movement by cluster. Track sinuosity was shown to increase from east to west. Only one cluster showed a statistically significant trend (decreasing) in TC frequency. The concept of TC power dissipation index (PDI) was introduced, revealing that two of the clusters have diverging trends for PDI post 2004. The location of cyclone maximum intensity (LMI) was trended, and only one cluster showed a statistically significant trend (towards the equator) for LMI. All these findings demonstrated a clear variance in risk between the clusters and suggests that this method of cluster analysis is a useful and productive complementary tool when establishing future impacts of TCs - the method identifies divergent TC characteristics and trends at a finer scale (cluster) level which then aids in assigning specific and differing TC risk mitigation strategies to different areas of the Australian east coast.

Subseasonal prediction of the 2020 Great Barrier Reef and Coral Sea marine heatwave

The 2020 marine heatwave in the Great Barrier Reef and Coral Sea led to mass coral bleaching. Sea surface temperature anomalies reached +1.7°C for the whole of the Great Barrier Reef and Coral Sea and exceeded +2°C across broad regions (referenced to 1990-2012). The marine heatwave reached Category 2 (Strong) and warm anomalies peaked between mid-February and mid-March 2020. The marine heatwave’s peak intensity aligned with regions of reduced cloud cover and weak wind speeds. We used a marine heatwave framework to assess the ability of an operational coupled ocean-atmosphere prediction system (ACCESS-S1) to capture the marine heatwave’s severity, duration, and spatial extent. For initial week predictions, the predicted marine heatwave severity generally agreed with the magnitude and spatial extent of the observed severity for that week. The model ensemble mean did not capture the marine heatwave’s development phase at lead times beyond the first week. The model underestimated the marine heatwave’s spatial extent, which reached up to 95% of the study area with at least Moderate severity and up to 43% with at least Strong severity. However, most forecast ensemble members correctly predicted the period of Strong severity in the first week of the model forecast. The model correctly predicted marine heatwave conditions to persist from mid-February to mid-March but did not capture the end of the marine heatwave. The inability to predict the end of the event and other periods of less skilful prediction were related to subseasonal variability owing to weather systems, including the passage of tropical cyclones not simulated in the model. On subseasonal timescales, evaluating daily to weekly forecasts of ocean temperature extremes is an important step toward implementing methods for developing operational forecast extremes products for use in early warning systems.

Aretopsis sandybrucei, a new deep-water shrimp (Malacostraca: Decapoda: Caridea: Alpheidae) from the Coral Sea

A new alpheid shrimp, Aretopsis sandybrucei sp. nov., is described on the basis of three specimens collected from three deep-water banks in the Chesterfield Plateau of the Coral Sea, between New Caledonia and Queensland, Australia, at a depth range of 280–550 m. The new species is the first known deep-water species of the genus Aretopsis De Man, 1910, with its two congeners, A. amabilis De Man, 1910 and A. manazuruensis Suzuki, 1971, being confined to the lower intertidal and shallow subtidal areas, to a maximum depth of 50 m. Based on morphological grounds, A. sandybrucei sp. nov. can be easily separated from A. amabilis and A. manazuruensis by the generally much stouter third to fifth pereiopods, with their dactyli each bearing a very small secondary unguis on the flexor margin, in comparison to a much stronger one in the other two species. Aretopsis sandybrucei sp. nov. also differs from A. amabilis and A. manazuruensis by the less contrasting colour pattern, including the more translucent, dull yellowish chelae and tail fan. An association of A. sandybrucei sp. nov. with a deep-water hermit crab appears to be highly likely due to the presence of several large hermit crabs (Paguridae) in at least one of the three dredge/bottom trawl hauls, which was also containing a paratype of the new species. The taxonomic status of A. amabilis and A. manazuruensis is discussed.

Hidden in the deep: distinct benthic trajectories call for monitoring of mesophotic reefs

Long-term monitoring studies are central to coral reef ecology and conservation management. However, ongoing monitoring programs are almost exclusively focused on shallow depths, and it remains unclear to what extent those are representative of the whole ecosystem. Here, we present a temporal comparison (2012-2017) of directly adjacent shallow and mesophotic benthic communities across seven sites from the Great Barrier Reef and Western Coral Sea. We found a positive correlation initially between shallow and mesophotic coral cover, with higher cover at shallow depths. However, this correlation broke down after multiple disturbances, with coral cover declining only at shallow depths. Point-based tracking revealed the dynamic nature of mesophotic communities, with their consistent coral cover reflecting a net balance between substantial growth and mortality. Overall, the divergent trajectories highlight the urgency to expand monitoring efforts into mesophotic depths, to decipher the processes governing these habitats and enable better-informed management of the overall ecosystem.

Taxonomic review of the subfamily Lohmannellinae (Acari: Trombidiformes: Halacaridae) with morphological comparisons among genera

Taxonomic review of the halacarid subfamily Lohmannellinae is carried out with regard to morphology, biology, habitat, geographical distribution, and bibliography. The subfamily is one of 16 subfamilies in the family Halacaridae and consists of five genera, Lohmannella, Porolohmannella, Scaptognathides, Scaptognathus, and Xenohalacarus, which include 38, 1, 11, 31, and 1 known species, respectively. The genera Scaptognathides, Scaptognathus, and Xenohalacarus are marine, Porolohmannella is a freshwater inhabitant, and Lohmannella lives in marine and freshwater. The species in this subfamily are mostly arenicolous and probably carnivorous or omnivorous in feeding habits. As for the geographic distribution, Lohmannella shows almost cosmopolitan distribution; Scaptognathus is also widely distributed except for polar regions. The genus Scaptognathides is distributed more in southern oceans than in the northern circle, and Xenohalacarus is restricted to the Coral Sea. The freshwater genus Porolohmannella has wide inland distribution except for the African, South American, Australian, and Antarctic continents. Based on morphological comparisons among five genera, Scaptognathus is regarded as the most unique taxon and Lohmannella and Porolohmannella as rather conservative taxa in the subfamily.