Guiding ecological principles for marine spatial planning

The declining health of marine ecosystems around the world is evidence that current piecemeal governance is inadequate to successfully support healthy coastal and ocean ecosystems and sustain human uses of the ocean. One proposed solution to this problem is ecosystem-based marine spatial planning (MSP), which is a process that informs the spatial distribution of activities in the ocean so that existing and emerging uses can be maintained, use conflicts reduced, and ecosystem health and services protected and sustained for future generations. Because a key goal of ecosystem-based MSP is to maintain the delivery of ecosystem services that humans want and need, it must be based on ecological principles that articulate the scientifically recognized attributes of healthy, functioning ecosystems. These principles should be incorporated into a decision-making framework with clearly defined targets for these ecological attributes. This paper identifies ecological principles for MSP based on a synthesis of previously suggested and/or operationalized principles, along with recommendations generated by a group of twenty ecologists and marine scientists with diverse backgrounds and perspectives on MSP. The proposed four main ecological principles to guide MSP—maintaining or restoring: native species diversity, habitat diversity and heterogeneity, key species, and connectivity—and two additional guidelines, the need to account for context and uncertainty, must be explicitly taken into account in the planning process. When applied in concert with social, economic, and governance principles, these ecological principles can inform the designation and siting of ocean uses and the management of activities in the ocean to maintain or restore healthy ecosystems, allow delivery of marine ecosystem services, and ensure sustainable economic and social benefits.     

Modelling and mass balance assessments of nutrient retention in a seasonally-flowing estuary (Swan River Estuary,Western Australia)

An integrated mass balance and modelling approach for analysis of estuarine nutrient fluxes is demonstrated in the Swan River Estuary, a microtidal system with strong hydrological dependence on seasonal river inflows. Mass balance components included estimation of gauged and ungauged inputs to the estuary and losses to the ocean (outflow and tidal exchange). Modelling components included estimation of atmospheric (N fixation, denitrification) and sediment–water column nutrient exchanges. Gross and net denitrification derived using two independent methods were significantly correlated (r² = 0.49, p < 0.01) with net rates averaging 40% of gross. Annual nitrogen (N) and phosphorus (P) loads from major tributaries were linearly correlated with annual freshwater discharge and were 3-fold higher in wet years than in dry years. Urban drains and groundwater contributed, on average, 26% of N inputs and 19% of P inputs, with higher relative contributions in years of low river discharge. Overall, ungauged inputs accounted for almost 35% of total nitrogen loads. For N, elevated loading in wet years was accompanied by large increases in outflow (7x) and tidal flushing (2x) losses and resulted in overall lower retention efficiency (31%) relative to dry years (70%). For P, tidal flushing losses were similar in wet and dry years, while outflow losses (4-fold higher) were comparable in magnitude to increases in loading. As a result, P retention within the estuary was not substantially affected by inter-annual variation in water and P loading (ca. 50% in all years). Sediment nutrient stores increased in most years (remineralisation efficiency ca. 50%), but sediment nutrient releases were significant and in some circumstances were a net source of nutrients to the water column.     

Benthic macrofauna and productivity regimes in the Barents Sea — Ecological implications in a changing Arctic

Benthic faunal assemblages were analysed from 47 stations in the central and southern parts of the Barents Sea, together with sedimentary and water column parameters, daily ice records and modelled integrated primary productivity. Sampling spanned areas influenced by Atlantic Water (AW) to those lying under Arctic Water (ArW), and included stations with mixed water masses. Ice cover suppressed water column productivity in the northern areas. Three main faunal groups were identified, based on similarity of numerical faunal composition. The northern and southern faunal groups were separated by the northernmost penetration of AW in the bottom water and the third group, the Hopen group, was influenced by modified bank water. Faunal abundances were significantly higher within the southern faunal group relative to the northern group, but the numbers of taxa present were similar. The particularly rich fauna of the Hopen group reflected sediment heterogeneity and tight pelagic–benthic coupling. These results suggest that a retreat and thinning of the ice cover in the Barents Sea likely will result in the northern parts of the Barents Sea becoming more Atlantic in character, with a higher productivity at the sea floor.     

Marine renewable energy and public rights

Marine renewable energy is likely to be an important part of UK energy policy over the next decades. A start has already been made, but to generate power on a significant scale requires the use of vast areas of ocean, on which there are competing claims. Legislation, and in particular the Energy Act 2004, goes a long way towards giving developers the legal infrastructure they need, to invest with confidence. But it is far from perfect, in dealing with important competing rights. This article has a narrow (but important) focus. It assumes that there are no problems over jurisdiction or international law. It is concerned principally with the rights of UK citizens. The issue is about reconciling the generation of large-scale marine renewable energy with other legitimate uses of the sea, and in particular fishing and navigation rights.     

First encounter with a live male blanket octopus: The world's most sexually size‐dimorphic large animal

The first encounter with a live male blanket octopus, Tremoctopus violaceus Chiaie, 1830, illustrates the most extreme example of sexual size‐dimorphism in a non‐microscopic animal. Females attain sizes of up to 2 m long—almost 2 orders of magnitude larger than the 2.4‐cm‐long male. Weight ratios between the sexes are at least 10 000:1 and are likely to reach 40 000:1. Sexual selection and the unique defensive strategy of carrying cnidarian stinging tentacles may both have contributed to the evolution of this extreme size‐dimorphism. Such dimorphism is not seen in any other animal remotely as large.     

Genetic variation and population structure in the New Zealand snapper

Fifteen proteins encoded by 23 gene loci were electrophoretically surveyed in two samples of snapper Chrysophrys auratus (Forster) from Wellington Harbour and the Hauraki Gulf. Between 17% and 26% of the loci examined were found to be polymorphic and the proportion of heterozygous loci per individual was 7.9% to 8.4%. Using Rogers’ genetic distance coefficient an overall similarity of 0.98 was calculated between the two samples.

Three polymorphic loci Est‐4, Gpi‐1, and Idh were examined in an additional 10 samples from around New Zealand. Two genetically distinct stocks were apparent: one along the west coast, the other along the east coast of the North Island. There was an indication of stock mixing at Ninety Mile Beach and in the Bay of Plenty and East Cape. The distribution of alleles at the Est‐4 locus revealed a third stock in Hawke Bay that is genetically more similar to the west coast than the east coast stock. Hydrological conditions in Hawke Bay are more similar to those of the west coast than to those of the north east coast of the North Island. Thus it is possible that Est‐4 alleles are selectively maintained in response to an environmental factor.     

Distribution and spatial variation of hydrothermal faunal assemblages at Lucky Strike (Mid-Atlantic Ridge) revealed by high-resolution video image analysis

Whilst the fauna inhabiting hydrothermal vent structures in the Atlantic Ocean is reasonably well known, less is understood about the spatial distributions of the fauna in relation to abiotic and biotic factors. In this study, a major active hydrothermal edifice (Eiffel Tower, at 1690 m depth) on the Lucky Strike vent field (Mid-Atlantic Ridge (MAR)) was investigated. Video transects were carried out by ROV Victor 6000 and complete image coverage was acquired. Four distinct assemblages, ranging from dense larger-sized Bathymodiolus mussel beds to smaller-sized mussel clumps and alvinocaridid shrimps, and two types of substrata were defined based on high definition photographs and video imagery. To evaluate spatial variation, faunal distribution was mapped in three dimensions. A high degree of patchiness characterizes this 11 m high sulfide structure. The differences observed in assemblage and substratum distribution were related to habitat characteristics (fluid exits, depth and structure orientation). Gradients in community structure were observed, which coincided with an increasing distance from the fluid exits. A biological zonation model for the Eiffel Tower edifice was created in which faunal composition and distribution can be visually explained by the presence/absence of fluid exits.     

The role of archaeological and cultural-historical records in long-range coastal fisheries resources management strategies and policies in the Pacific Islands

The usefulness of conventional fisheries science for long-term fisheries management and policies in the resource-poor islands of the Pacific is very limited. Fishery managers can, however, make use of such alternative sources of information as archaeological and historical data to develop fishery management initiatives. Most Pacific Islands were settled by humans over the last three millennia, although human settlement in Western Melanesia dates from the late Pleistocene, a period of about 40 millennia. Archaeological studies over the past half-century contain information on the long-term subsistence exploitation of fish and invertebrates from nearshore coral reefs and lagoons. Molluscs appear to have been a very important food source for early human colonists in the Pacific Islands, but declines in abundance through harvest pressure and environmental changes forced a greater reliance on fin-fish capture and on agriculture. There is no firm evidence from the archaeological record to suggest that long-term subsistence exploitation of reef fish populations has had any serious negative effects on abundance or structure of reef fish communities. Sources for more recent historical information are also exemplified and briefly examined for their usefulness in assessing the impacts of commercial fishing. It is argued that fishery managers who adopt a data-less approach to fishery management could profitably use these sources of information to enrich their assessment of the impacts of various management scenarios.