Holocene benthic foraminiferal assemblages indicate long-term marginality of reef habitats from Moreton Bay, Australia

Since European settlement (ca. 1824 CE), the subtropical inshore reefs of Moreton Bay have undergone rapid deterioration in water quality from changes in land-use practices, resource exploitation and rapid population growth, spurring marine managers to assess the drivers of ecological shifts. However, the short temporal-scale of most studies is an inadequate baseline for understanding the severity and magnitude of biological response. We present millennial-scale records employing palaeoecological and quantitative multivariate techniques within a concise chronological framework to analyse benthic foraminiferal community structure of reefs in Moreton Bay, Queensland. Well-constrained, UM-dated, millennial-scale records from sediment cores were used to document the long-term response of foraminifers to natural environmental variability. The temporal and spatial distribution patterns of foraminifers reveal long-term marginality throughout the similar to 7400 years of Holocene history, prior to European settlement. While specific faunal response to the effects of relative ENSO-climate and sea level fall are difficult to disentangle, the earlier phases of reef development are already represented by marginal taxa indicating possibly an earlier response to a decline in conditions. Overall, long-term consistency in conditions favoured two types of low diversity reef assemblages: 1) high density of small, heterotrophic and opportunistic species and 2) low density of photosymbiotic foraminiferal assemblages. Comparison of foraminiferal community composition between the Holocene and the present day indicates overlap in species composition supporting long-term marginality, particularly in the Western Bay. Such combined palaeoecological and recent studies can benefit long-term initiatives for monitoring present and future water quality conditions in the Bay's reef habitats. (C) 2014 Elsevier B.V. All rights reserved

Simple rules can guide whether land or ocean based conservation will best benefit marine ecosystems

Coastal marine ecosystems can be managed by actions undertaken both on the land and in the ocean. Quantifying and comparing the costs and benefits of actions in both realms is therefore necessary for efficient management. Here, we quantify the link between terrestrial sediment run-off and a downstream coastal marine ecosystem, and contrast the cost-effectiveness of marine and land-based conservation actions. We use a dynamic land- and sea-scape model to determine whether limited funds should be directed to one of four alternative conservation actions – protection on land, protection in the ocean, restoration on land, or restoration in the ocean – to maximise the extent of light-dependent marine benthic habitats, across decadal time-scales. We apply the model to a case study seagrass meadow in Australia. We find that marine restoration is the most cost-effective action over decadal time-scales in this system, based on a conservative estimate of the rate at which seagrass can expand into new habitat. The optimal decision will vary in different social-ecological contexts, but some basic information can guide optimal investments to counteract land and ocean based stressors: (1) marine restoration should be prioritised if the rates of marine ecosystem decline and expansion are similar and low; (2) marine protection should take precedence if the rate of marine ecosystem decline is high, or if the adjacent catchment is relatively intact and has a low rate of vegetation decline; (3) land-based actions are optimal when the ratio of marine ecosystem expansion to decline is >1.4, with terrestrial restoration typically the most cost effective; and (4) land protection should be prioritised if the catchment is relatively intact, but the rate of vegetation decline is high. These rules-of-thumb illustrate how cost-effective conservation outcomes for connected land-ocean systems can proceed without complex modelling

Coral and micro-benthic assemblages from reef habitats in Moreton Bay

The subtropical coral reefs of Moreton Bay support a rich diversity of corals and micro-benthic organisms. These high-latitude reef communities exist in marginal environments that include relatively cooler, more light-limited, and more variable environmental conditions than those in the tropics. Holocene reef coral communities formed episodically over the Bay’s 7000-year history, with a high degree of persistence in community structure and reef accretion rate until European colonisation of the Queensland coastline. However, during the most recent phase of the Bay’s reef development, reductions in water quality have transformed the Bay’s coral assemblages from predominantly large, fast-growing and branching acroporid corals to predominantly slower growing and smaller massive corals. The modern composition and diversity of benthic foraminiferal and micro-molluscan communities is driven mainly by substrate and water-quality parameters and shows a striking gradient from the variable and stressed water conditions of the western Bay to the more open-marine higher water quality habitats of the eastern Bay, including Myora Reef. Episodic changes also occurred in the Holocene benthic microfaunal composition, confirming the fluctuating nature of the Bay’s marine environments. Recent increases in foraminifera diversity and symbiont-bearing taxa signals a subtle improvement in water quality from the 1970s to 2008; however, for micro-gastropods, comparisons between fossil and modern death assemblages illustrate a decline in the condition of modern Bay habitats. The Holocene variation in the taxonomic composition and diversity of coral and micro-benthic assemblages of Moreton Bay reveals a history of recovery and rapid reef growth. Rapid recovery may still be possible if the causes of anthropogenic degradation are reversed and for this the highest priority is to reduce sediment and nutrient delivery into the Bay’s marine habitats

Changes in coral reef communities among the Florida Keys 1996-2003

Hard coral (Scleractinia and Milleporina) cover data were examined from 37 sites surveyed annually from 1996 to 2003 in the Florida reef tract, USA. Analyses of species numbers and total cover showed that site-to-site differences were generally very much greater than differences among times within sites. There were no significant differences among different geographical areas within the reef tract (Upper, Middle and Lower Keys). Large-scale changes documented included a reduction in species numbers and total cover on both deep and shallow offshore reefs between 1997 and 1999 followed by no recovery in cover, and only scant evidence of any recovery in species numbers by 2003. These changes coincided with bleaching events in 1997 and 1998, and the passage of Hurricane Georges through the Lower Keys in 1998. The lack of recovery among offshore reefs suggests that they were no longer resilient. Multivariate analyses revealed that some sites showed relatively little temporal variation in community composition, essentially random in direction, while others showed relatively large year-on-year changes. There was little evidence of any major region-wide changes affecting assemblage composition, or of any events that had impacted all of the sampling sites in any single year. Instead, different sites exhibited differing patterns of temporal variation, with certain sites displaying greater variation than others. Changes in community composition at some sites are interpreted in the light of knowledge of events at those sites and the relative sensitivities of species to various stressors, such as changes in cover of Acropora palmata and Millepora complanata at Sand Key following the bleaching events and hurricane in 1998, and declines in Montastraea annularis at Smith Shoal following a harmful algal bloom in 2002. For most sites, however, it is impossible to determine the causes of observed variation

Incorporating historical perspectives into systematic marine conservation planning

Historical perspectives are highly relevant to marine conservation, yet rarely integrated into ocean planning efforts. By its nature, marine conservation planning is forward looking-concerned with measures that should be taken in the future. It usually focuses on mitigating anticipated adverse changes caused by current and future human activities, with the implicit assumption that present or recent conditions should be maintained. In this chapter, we show that without incorporating historical data and analysis, such approaches will, in the best case, cause us to aim too low; and in the worst case, they can result in inappropriate targets for planning and management. We review the role that historical perspectives can provide in marine conservation planning, highlight planning exercises in which this has occurred or has been discussed, and provide recommendations for researchers and planning practitioners. Using the systematic conservation planning framework, we show that each planning stage can greatly benefit from a historical perspective and illustrate that failure to consider historical information reduces the effectiveness of marine conservation planning. We posit that historical perspectives may shift the conservation focus from restoring previous ecosystem states to recovering critical ecosystem functions and processes that maintain resilience. Historical perspectives can fundamentally change the conservation vision for a region, providing a window into possibilities for the future

An End to Settlement on the Courthouse Steps - Mediated Settlement Conferences in North Carolina Superior Courts

Animal forests form the foundation of many important marine benthic habitats. However, a near ubiquitous lack of long-term scientific data raises significant challenges in assessing how these communities have changed over time in response to human impacts and how they might respond to future perturbations. To address these questions, alternative sources of data have to be gathered. Marine historical ecology is a rapidly growing field of research that uses historical sources to challenge our assumptions about what is natural in our marine environments. This discipline thus has the potential to fill some of the gaps in our understanding of animal forests through time. This chapter reviews how historical ecology research helps us to better understand the changes that have occurred in marine animal forests, focusing in particular upon oyster and shallow-water coral communities. The variety of data sources available and the methodologies that have been used to uncover past changes in these and related ecosystems are highlighted. The use of historical data to inform restoration efforts and emerging concepts in marine ecology, such as ecosystem service provision, is examined. Finally, the limitations of historical data and remaining knowledge gaps with regard to past animal forest communities are discussed

Millennium-scale records of benthic foraminiferal communities from the central Great Barrier Reef reveal spatial differences and temporal consistency

Understanding long-term community dynamics and the ways in which they respond to major disturbances is a central management theme within coastal marine ecosystems. River outputs from the Queensland coastline directly affect inshore marine communities of the Great Barrier Reef (GBR), Australia. Of these, the Burdekin River exports the highest volume of terrestrial runoff. Following European settlement in the mid-19th century, over three quarters of the native vegetation from the Burdekin catchment were cleared for agricultural purposes. Despite such extensive historical catchment modification, the impact of these changes on the inshore GBR is largely unknown, primarily due to the paucity of long-term ecological data. To assess the effects of modem land-use change on inshore reef environments and to establish an historical baseline of community structure, we examined the sedimentary geochemistry and benthic foraminiferal assemblages of eight sediment cores collected from two coral reefs situated inside (Pandora) and outside (Havannah) an inner-shelf sediment prism formed during the Holocene. Foraminiferal community structure was reconstructed from the past millennium, and the time series was constrained using U-series dating of coral fragments within the cores. Environmental records were reconstructed using stable carbon isotopes (delta C-13) and elemental C:N ratios from bulk sediment samples. Non-parametric analysis of community structure in benthic foraminifers indicated no change in community structure through time at either reef. Despite this apparent ecological persistence through time, significant differences in foraminiferal community structure were observed between the two reefs. The communities were clearly characterized by different functional groups; heterotrophic genera were persistent within, and symbiont-bearing genera were persistent outside, the Holocene inshore sediment wedge. We found no difference in the source of organic matter (interpreted from delta C-13 values) either between reefs or through time, yet elemental C:N ratios indicated a difference in the amount of organic matter between reefs. The influence of the Holocene inshore sediment wedge was demonstrated by the dissimilarity in sedimentary C:N ratios between the two reefs. (C) 2013 Elsevier B.V. All rights reserved