%0 Journal Article %J PloS One %D 2020 %T Monitoring the resilience of a no-take marine reserve to a range extending species using benthic imagery %A Nicholas R. Perkins %A Hosack, G.R. %A Scott D Foster %A Jacquomo Monk %A Neville Barrett %K auv %K barren climate change %K benthic imagery %K Centrostephanus rodgersii kelp loss %K temperate reef %K time-series %K urchin %X

IMAS, as part of NESP Hub-related research, have been monitoring reefs on Tasmanian east coast over the past decade or more, using an Autonomous Underwater Vehicle supplied by IMOS. The vehicle takes high resolution images of the seabed at a wide range of depths, especially at depths below which we can survey via our standard dive-based monitoring programs. these images are analysed to generate biodiversity and habitat data from the shallowest reefs down to the deepest parts of east coast reef systems (in excess of 60 m). In this paper we use this data to examine the extent that urchin barrens formed by overgrazing by the extension of Centrostephanus rodgersii (Long-spined urchin) has impacted east coast reef systems, how this varies with depth, and how this has changed with time. Importantly we also contrast the response between a no-take marine reserve at Governor Island (off Bicheno) and identical habitats in adjacent fished areas. We found that the large lobster population that has built up in the MPA has helped the reserve be resilient to the urchin invasion, with barren being far less common in the reserve than outside. Despite the good news that natural populations in protected areas are able to offer significant resistance to urchin invasion, there is also the bad news that urchin barrens are continuing to increase through time on eastern Tasmanian reefs, and their cover has essentially doubled over the five year period of the surveys (2011-2016). This equates going from around 0.3% to 0.8% cover within the park, and from around 3% to around 7% outside the park over that time period (although this varied between locations surveyed). Dr Nick Perkins and colleagues used a complex modelling approach to deal with a range of spatial issues in the sampling design to ensure the significance of the patterns observed was tested properly. This design is probably the most important part of the paper from the science perspective, but the ecological results have important implications for MPA, off-reserve biodiversity and fisheries management.

%B PloS One %V 15 %8 12 Aug 2020 %G eng %U https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0237257 %N 8 %9 Journal %R 10.1371/journal.pone.0237257 %0 Journal Article %J Methods in Ecology and Evolution %D 2014 %T Choosing between strategies for designing surveys: autonomous underwater vehicles %A Scott D Foster %A G.R. Hosack %A Nicole A. Hill %A Neville Barrett %A Vanessa L Lucieer %E Spencer, Matthew %K autocorrelation %K autonomous underwater vehicles %K Geostatistics %K GRTS %K integrated nested laplace approximation %K matérn %K model-based design %K temperate reef %X
  1. Autonomous underwater vehicles (AUV), which collect images of marine habitats, are now an established sampling tool. The use of AUVs is becoming more widespread as they offer a non-destructive method to survey substantial spatial areas. The design of AUV surveys has historically been based on expert knowledge and AUV-specific considerations, such as reducing geolocation error. The expert knowledge encompasses intuition, previous surveying experiences and holistic knowledge of the study region.
  2. We investigate the statistical aspects to AUV survey design for estimation of percentage cover of key benthic biota. We investigate the presence of spatial autocorrelation in AUV data using model-based geostatistics and examine the effect of autocorrelation on survey design by examining different design strategies – methods for placing AUV transects. The design strategies are assessed by inspecting the expected bias and the expected standard deviation of model predictions, where the model depends on the choice of design.
  3. The AUV data exhibited a wide range of autocorrelation, from non-existent to substantial. The design strategies varied in their statistical performance and nearly all strategies had shortcomings. Design strategies that were consistently poor performers had (i) transects placed in parallel in a single spatial dimension and (ii) made no attempt to spread out the transects in space. The superior design types had more transect-to-transect separation (but not too much) and effectively spanned important covariates.
  4. The results give guidelines to researchers designing AUV surveys for biological mapping and for monitoring. In particular, we demonstrate that any spatial design should seek spatial balance, such as would be introduced by a systematic or stratified component within a randomized design. Knowledge of the system under study should be incorporated and, if possible, should be done so in a formal manner that is objective and repeatable.
     
%B Methods in Ecology and Evolution %V 5 %P 287 - 297 %8 03 Jan 2014 %G eng %U http://doi.wiley.com/10.1111/2041-210X.12156 %N 3 %! Methods Ecol Evol %R 10.1111/mee3.2014.5.issue-310.1111/2041-210X.12156