Aim We aimed to redress a current limitation of local ecological studies (i.e. piecemeal information on specific taxa) by integrating existing ecological knowledge with quantifiable patterns in primary habitat (i.e. composition, distribution and cover) from local to continental scales. By achieving this aim, we sought to provide a biogeographical framework for the interpretation of variation in the ecology of, and threats to, subtidal rocky landscapes.Location The subtidal rocky coast of continental Australia, with longitudinal comparisons spanning > 4000 km of southern coast (115°03¢ E-153°60¢ E) between latitudes of 33°05¢ S and 35°36¢ S, and latitudinal comparisons across 26°40¢ S to 37°08¢ S of eastern Australia.Methods The frequency and size of patches of major benthic habitat were quantified to indicate contemporary function (ecology) and to establish patterns that may result from contrasting regional-scale processes (biogeography). This was achieved by quantifying the composition and patchiness of key subtidal habitats across the continent and relating them to the known ecology of subsets of locations in each region. A nested design of several spatial scales (1000s, 100s, 10-1 km) was adopted to distinguish patterns at local through to biogeographical scales. ResultsWe show biogeography (in terms of longitude and latitude) to have a fundamental influence on the patterns of abundance and composition of subtidal habitats across regional (1000s of kilometres) to local (10s of kilometres to metres) scales. Across the continent, the most fundamental patterns related to (1) the proportion of rock covered by kelp forests, as related to particular functional groups of herbivores, and (2) the small-scale heterogeneity (metres) that characterizes these forests. Main conclusionsWe interpret these results within a framework of alternative processes known to maintain habitat heterogeneity across these regions (e.g. productivity versus consumption as shapers of habitat structure). These interpretations illustrate how regional differences in ecological patterns and processes can create contradictory outcomes for the management of natural resources. We suggest that researchers and managers of natural resources alike may benefit from understanding local issues (e.g. the effects of fishing and its synergies with water pollution) in their biogeographical contexts.

One of the most striking and widespread patterns observed on subtidal rocky reefs is that up-facing surfaces are monopolized by algae, whereas down-facing surfaces are dominated by sessile invertebrates. This study experimentally assessed the model that light and sedimentation interact with surface orientation to maintain this pattern of habitat heterogeneity. We tested the hypothesis that if epibiotic assemblages on down-facing surfaces were rotated to face upward, then the least change in assemblage structure would occur on shaded surfaces with reduced rates of sedimentation. In general, the alternate states of algal vs invertebrate dominated assemblages appeared to be primarily maintained by light intensity, which facilitated the cover of algae on up-facing surfaces (full light) and invertebrates on down-facing surfaces (reduced light). Although sedimentation was only partially responsible for differences between habitat types, it acted as a negative disturbance on the abundance of algae and survivorship of invertebrates. When combined with differences in light intensity, high rates of sediment accumulation had slight negative effects under natural light, but under shaded conditions these negative effects were substantially increased, causing changes to the structure of the whole assemblage. This result warns that attempts to identify the effects of sedimentation in isolation from light intensity, which depends on factors such as turbidity, may not reveal the true effects of sedimentation on epibiotic assemblages. The ability of invertebrates to withstand high rates of sediment accumulation was related to their morphology, whereby erect forms growing above accumulated sediments had greater rates of survivorship than prostrate growth forms, which tended to be smothered by sediments. To properly understand the physical processes of facilitation (e.g. light intensity) and disturbance (e.g. sedimentation) we need to assess them in meaningful combinations so that explanations of assemblage structure do not create the false impression that such processes, however complex, produce only small effects relative to other processes.

Seagrasses are important marine ecosystems situated throughout the world's coastlines. They are facing declines around the world due to global and local threats such as rising ocean temperatures, coastal development and pollution from sewage outfalls and agriculture. Efforts have been made to reduce seagrass loss through reducing local and regional stressors, and through active restoration. Seagrass restoration is a rapidly maturing discipline, but improved restoration practices are needed to enhance the success of future programs. Major gaps in knowledge remain, however, prior research efforts have provided valuable insights into factors influencing the outcomes of restoration and there are now several examples of successful large-scale restoration programs. A variety of tools and techniques have recently been developed that will improve the efficiency, cost effectiveness, and scalability of restoration programs. This review describes several restoration successes in Australia and New Zealand, with a focus on emerging techniques for restoration, key considerations for future programs, and highlights the benefits of increased collaboration, Traditional Owner (First Nation) and stakeholder engagement. Combined,

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