Aquatic Conservation: Marine and Freshwater Ecosystems

In some localities, their contribution to coastal defence and to tourism and regional character have been acknowledged in local plans, but this is far from ubiquitous.

A rapid assessment was undertaken of the range of ecosystem services provided by coastal sand dune systems, using the Millennium Ecosystem Assessment ecosystem services classification augmented with habitat‐ and locally‐appropriate additions.

Sand dunes were shown to provide a wide range of provisioning, regulatory, cultural and supporting services, many of which remain substantially overlooked.

Although the importance of coastal sand dune for a diversity of characteristic and often rare organisms from a variety of taxa has been addressed, many of the broader ecosystem services that these habitats provide to society have been overlooked. This suggests that coastal sand dune systems are neglected ecosystems of significant and often under‐appreciated societal value. Copyright © 2010 John Wiley & Sons, Ltd.

The causes of these declines include hydrological alterations, habitat degradation and loss, overexploitation, invasive species, pollution, and the multiple impacts of climate change. Although there are policy initiatives that aim to protect freshwater life, these are rarely implemented with sufficient conviction and enforcement. Policies that focus on the development and management of fresh waters as a resource for people almost universally neglect the biodiversity that they contain.

Here we introduce the Alliance for Freshwater Life, a global initiative, uniting specialists in research, data synthesis, conservation, education and outreach, and policymaking. This expert network aims to provide the critical mass required for the effective representation of freshwater biodiversity at policy meetings, to develop solutions balancing the needs of development and conservation, and to better convey the important role freshwater ecosystems play in human well‐being. Through this united effort we hope to reverse this tide of loss and decline in freshwater biodiversity. We introduce several short‐ and medium‐term actions as examples for making positive change, and invite individuals, organizations, authorities, and governments to join the Alliance for Freshwater Life.

Schemes to classify habitats at local and regional scales, according to their geophysical properties, may identify different factors as determinants, and/or use them in different sequences in a hierarchical classification. We examined the reasons for these differences in local and regional applications of a global concept, and argue that a common set of factors could be applied in a defined and defensible sequence to produce a common hierarchy of habitat types among geographic regions.

We show how simple mapping and GIS techniques, based on readily available data, can lead to the identification of representative habitat types over broad geographic regions. We applied a geophysical framework first to the entire Canadian coastline and second to the Scotian Shelf of Atlantic Canada to establish broad scale marine natural regions and ‘seascapes’, respectively. This ecosystem level approach — which defines representative habitat types — is a fundamental prerequisite for many purposes. It can form the basis for further analyses including: definition of community types from habitat — community relationships; evaluation of the potential roles of focal species in marine conservation; evaluation of candidate marine protected areas; definition of unaffected reference areas against which the effects of human activities can be gauged; guidance for water quality monitoring studies; management of marine resources.

Community resistance to MPA proposals from centralized agencies can be addressed through effective participatory processes with consistent engagement over time, transparency, and the incorporation of benefits for communities.

Indigenous communities in particular are becoming key actors of some conservation initiatives (e.g. MPAs) and recognition of their inherent rights, traditional knowledge and deep connections to the marine environment can become the foundations for collaborative management of MPAs.

True participation requires empowerment for engagement, and this in turn requires education and capacity building for local people to get involved in the process of planning, implementing, and managing MPAs.

How bottom‐up and top‐down approaches are used should consider the scale of the MPA (e.g. small vs. large), the geographic scenario (e.g. coastal vs. remote), the level of anthropogenic influence, the conservation objectives (e.g. species, habitats, ecosystems), the political and governance context, and specific cultural conditions, such as the presence of indigenous communities.

The facilitative effect of the beaver Castor canadensis on a waterbird community of seven species of waders and ducks in boreal ponds was studied by using the before–after control–impact method (BACI) and analysing the effect of the duration of flooding. The before–after setting could be used since beavers had caused disturbance by flooding several forest ponds during the course of this long‐term study (1988–2009). The study took place in southern Finland, where waterbirds were surveyed four times during the breeding season.

The number of waterbird species per pond per year was significantly higher during beaver inundation than before beaver activity, as was the waterbird abundance per survey. Changes were negligible in the controls. The numbers of all seven species increased during flooding, although the increase was significant in only three species. Common teal Anas crecca and green sandpiper Tringa ochropus showed the most positive numerical response to flooding. Mallard Anas platyrhynchos and wigeon Anas penelope were new species entering the duck guild in the flooded wetlands. The beneficial effect of the flood lasted the whole period of inundation, although the most substantial increase in species number appeared during the first two years of flooding.

The beaver acted as a whole‐community facilitator for waterbirds. It was inferred from previous studies that this was done by modifying the habitat to make it more productive and structurally favourable. It is concluded that favouring beavers is a worthwhile tool in restoring wetlands to promote waterbird communities.

The paper reviews existing knowledge and understanding of the exposure of marine ecosystems to ocean‐atmospheric changes, the consequences of these changes for marine fisheries in the UK and Ireland, and the adaptability of the UK and Irish fisheries sector.

Ocean warming is resulting in shifts in the distribution of exploited species and is affecting the productivity of fish stocks and underlying marine ecosystems. In addition, some studies suggest that ocean acidification may have large potential impacts on fisheries resources, in particular shell‐forming invertebrates.

These changes may lead to loss of productivity, but also the opening of new fishing opportunities, depending on the interactions between climate impacts, fishing grounds and fleet types. They will also affect fishing regulations, the price of fish products and operating costs, which in turn will affect the economic performance of the UK and Irish fleets.

Key knowledge gaps exist in our understanding of the implications of climate and ocean chemistry changes for marine fisheries in the UK and Ireland, particularly on the social and economic responses of the fishing sectors to climate change. However, these gaps should not delay climate change mitigation and adaptation policy actions, particularly those measures that clearly have other ‘co‐benefits’. Copyright © 2012 John Wiley & Sons, Ltd.

Despite growing interest in reintroduction programmes, surprisingly little is known about the ecology of beaver in dryland streams, and science to guide management decisions is often fragmented and incomplete.

This paper reviews the literature addressing the ecological effects and management of beaver activity in drylands of North America, highlighting conservation implications, distinctions between temperate and dryland streams, and knowledge gaps.

Well‐documented effects of beaver activity in drylands include changes to channel morphology and groundwater processes, creation of perennial wetland habitat, and substantial impacts to riparian vegetation. However, many hypothesized effects derived from temperate streams lack empirical evidence from dryland streams.

Topics urgently in need of further study include the distribution and local density of beaver dams; consequences of beaver dams for hydrology and water budgets; and effects of beaver activity on the spread of aquatic and riparian non‐native species.

In summary, this review suggests that beaver activity can create substantial benefits and costs for conservation. Where active beaver introductions or removals are proposed, managers and conservation organizations are urged to implement monitoring programmes and consider the full range of possible ecological effects and trade‐offs.

Manor Farm in Norfolk, UK, possesses around 40 ponds, and each year three to four ponds are subject to management involving tree (de‐shading) and/or sediment removal. To determine the consequences of management for pond biodiversity, macrophyte and invertebrate communities were surveyed for replicate ponds covering four ‘time since management’ categories: no management, and managed over the periods 1999–2003, 2004–2006 and 2007–2009.

Macrophyte diversity was significantly lower in unmanaged ponds compared with ponds managed in 2004–2006 and 2007–2009. In addition, with the exception of Mollusca, invertebrate diversity was significantly lower in the unmanaged ponds compared with all the managed ponds. A tendency was evident for diversity to peak 3–5 years after management and for a subsequent decline in diversity (significant for macrophytes). No distinctive species assemblages were associated with the different pond successional stages, although several species were confined to individual ponds. Although many species were absent from the non‐managed ponds, especially in the macrophytes and Coleoptera, few species were unique to these ponds.

The principal driver of species turnover in the ponds was shade, which was negatively correlated with macrophyte cover. Shade was substantially higher in the unmanaged ponds, whose species‐poor assemblages appeared to be a consequence of low oxygen levels. By arresting succession and restoring macrophyte‐dominated early‐ and mid‐successional ponds, management may have an essential role in biodiversity conservation. In pond‐rich landscapes, where a high proportion of ponds are heavily terrestrialized, management provides a sustainable means both of preserving heterogeneity in the pond network and preventing the loss of large numbers of species which favour early‐ and mid‐successional ponds. Copyright © 2012 John Wiley & Sons, Ltd.