Data describing post-recruit (adult) fish assemblages and the abundance of recruiting cryptobenthic species associated with 28 artificial reefs of different sizes and supporting different densities of transplanted kelp (Ecklonia radiata) off the west coast of Maria island. Adult assemblages were assessed using diver-based visual surveys conducted at three times (early: spring 2015, middle: autumn: 2016, late: spring 2016). At each time, 2 surveys were conducted, and the results were averaged. Recruiting cryptobenthic fishes were assessed using SMURF (standard Monitoring Units for the Recruitment of Fishes) collectors that were deployed for a six-week period in the centre of each reef on four consecutive occasions (November 2015 to March 2016).

Mesozooplankton community composition and structure were examined throughout the D’Entrecasteaux Channel, Huon Estuary and North West Bay, Tasmania, from November 2004 to October 2005, the data represented by this record was collected on the 08/06/2005. The composition of the mesozooplankton community was typical of inshore, temperate marine habitats, with seasonally higher abundance in summer and autumn and lower numbers in winter and spring. Copepods were the largest contributors to total abundance across all seasons and stations, while cladocerans and appendicularians were proportionally abundant in spring and summer. The faecal pellets of these three main groups, along with those of krill and amphipods, also contributed significantly to material recovered from sediment traps. Meroplanktonic larvae of benthic animals showed short-term peaks in abundance and were often absent from the water column for long periods. Spatially, North West Bay and the Channel had a higher representation of typically marine species, including Calanus australis and Labidocera cervi, while truly estuarine species, such as the copepod Gladioferens pectinatus, were more important in the Huon Estuary.

Inter-moult duration in giant crabs (Pseudocarcinus gigas) was estimated by an alternative method to utilising tag-recovery data. Reproduction in female giant crabs occurs in annual cycles, although females occasionally “skip” a reproductive season and do not become ovigerous; it has been noted previously that this appears to be associated with molting. Thus the proportion of females that do not participate in reproduction may indicate the proportion molting. This approach was tried with a sample of 342 females and the number that were “skipping” a reproductive season was measured by computerized tomography scanning (CT-scanning) of their ovaries prior to the extrusion of eggs. Radiometric aging (228Th/ 228Ra) of carapaces was also undertaken with the focus of this work on testing an assumption of the method, rather than describing the intermolt duration of a population.

The data is quantitative abundance of fish and megafaunal invertebrates and algal % cover derived from transect based counts at a wide range of locations across Temperate Australia. The methods are described in detail in Edgar and Barrett (1997). Primarily the data are derived from transects at 5 m depth and/or 10 m depth at each site surveyed. Methods were initially developed for research on temporal changes following protection in Tasmanian MPAs (Maria Is, Tinderbox, Ninepin Point, Governor Island). Further research has collected data in Tasmania, in MPA planning surveys (e.g. St Helens, Waterhouse Region, Low Head, Lillico Beach, Rocky Cape), an oil spill assessment (Low Head), and in studies and surveys in new Tasmania MPAs (Port Davey and the Kent Group). The data represented by this record was collected in MPA planning surveys and for opportunistic surveys such as the Low Head oil spill assessment. In many cases the dataset involved temporal replication (year scale).

Adult and sub-adult Red handfish (Thymichthys politus) and Spotted handfish (Brachionichthys hirsutus) preserved specimens and underwater images were used for analysing morphometrics (comprising of specimens from the CSIRO Australian National Fish Collection and underwater images). Individuals were measured for the morphological traits using electronic callipers (±0.1 mm) for preserved specimens and using Image J software for digital records. Note digital image size calibration occurred using a ruler in images or from size taken in situ. The purpose was to investigate whether external morphometrics could be used to determine sex in handfishes.

Most research investigating how ocean warming and acidification will impact marine species has focused on visually dominant species, such as kelps and corals, while ignoring visually cryptic species such as crustose coralline algae (CCA). CCA are important keystone species that provide settlement cues for invertebrate larvae and can be highly sensitive to global ocean change. However, few studies have assessed how CCA respond to low emission scenarios or conditions. In a laboratory experiment, we examined the responses of temperate CCA assemblages to combined warming and acidification projected under low, medium, and high emissions. Net calcification and net photosynthesis significantly declined in all emissions scenarios, while significant reductions in relative growth rates and increases in percentage bleaching were observed in the highest emission scenario. The negative responses of CCA to both low and medium emissions suggest that they may be adversely impacted by combined warming and acidification by 2030 if current emissions are sustained. This will have far reaching consequences for commercially important invertebrates that rely on them to induce settlement of larvae. These findings highlight the need to take rapid action to preserve these critical keystone species and the valuable services they provide.

Reef Life Survey is a program that trains and assists a network of skilled and committed recreational divers to cost-effectively assess the state of the inshore marine environment at the continental scale. The program uses standardised underwater visual census methods employed by SCUBA divers to survey fish and invertebrate species and to record macroalgal and coral cover using photo quadrats - this record refers to the website for this program. By standardising techniques and establishing a monitoring system on a nation-wide scale, the program addresses many of the current problems associated with managing the marine environment, including the paucity, patchiness and variable quality of data on the distribution of and trends to marine biodiversity. A central database is managed for the storage, analysis and dissemination of data collected nationally, with a publicly-accessible web-based portal. The website allows information collected on Australia's marine environment to be accessed in a meaningful form by policy-makers and the general public, including recreational groups, scientists and industry. It also has information and resources for particpating divers and those wishing to become involved. The dataset generated by recreational divers will provide a national framework for monitoring the state of the inshore environment and the identification of those threats and locations of greatest conservation concern. This record points to the online resource for Reef Life Survey: http://www.reeflifesurvey.com/

We used an in situ manipulative experiment to assess the impacts of the introduced New Zealand screwshell, Maoricolpus roseus, on native soft-sediment community structure and habitat characteristics in SE Tasmania. Impacts were assessed for high and low screwshell density and for the effect of live and dead screwshells, as well as those containing hermit crabs.