To save content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about saving content to .
To save content items to your Kindle, first ensure email@example.com
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
The rocky shores of the north-east Atlantic have been long studied. Our focus is from Gibraltar to Norway plus the Azores and Iceland. Phylogeographic processes shape biogeographic patterns of biodiversity. Long-term and broadscale studies have shown the responses of biota to past climate fluctuations and more recent anthropogenic climate change. Inter- and intra-specific species interactions along sharp local environmental gradients shape distributions and community structure and hence ecosystem functioning. Shifts in domination by fucoids in shelter to barnacles/mussels in exposure are mediated by grazing by patellid limpets. Further south fucoids become increasingly rare, with species disappearing or restricted to estuarine refuges, caused by greater desiccation and grazing pressure. Mesoscale processes influence bottom-up nutrient forcing and larval supply, hence affecting species abundance and distribution, and can be proximate factors setting range edges (e.g., the English Channel, the Iberian Peninsula). Impacts of invasive non-native species are reviewed. Knowledge gaps such as the work on rockpools and host–parasite dynamics are also outlined.
Coastal ecosystems are particularly vulnerable to alien invasions. Regular, standardized, targeted monitoring of coastal areas helps to detect the arrival of non-native species early, identify sites most vulnerable to invasion, and assess potential for further spread. This study quantified the spread and changes in distribution of non-native oyster, Crassostrea gigas, populations around the coast of Ireland. In total 37 sites were surveyed, in areas which either currently or previously harboured cultivated C. gigas, for the presence and abundance of ‘wild’ C. gigas. Wild populations were identified at 20 sites and at four additional sites C. gigas was observed as recently discarded from aquaculture activity. Five of the invaded sites were identified as being highly suitable for a population expansion based on their current population status. Importantly, we also identified individuals of C. gigas and native European oysters, Ostrea edulis, co-occurring within the same shore at five sites. This is the first record to our knowledge of such co-occurrence within Europe. This evidence of co-existing oyster species raises concerns regarding the potential impact of C. gigas on recovering O. edulis populations. In Ireland, however, C. gigas does not typically spread extensively from introduction points, and although self-containing populations exist, they are currently sustained at a much lower density than those observed in other regions such as the Wadden Sea or French Atlantic coasts. We suggest, therefore, that to protect native oyster populations, C. gigas should be eradicated where co-occurring with O. edulis and recommend continuous monitoring of invaded sites.
In the frame of the COST ACTION ‘EMBOS’ (Development and implementation of a pan-European Marine Biodiversity Observatory System), coverage of intertidal macroalgae was estimated at a range of marine stations along the European coastline (Subarctic, Baltic, Atlantic, Mediterranean). Based on these data, we tested whether patterns in macroalgal diversity and distribution along European intertidal rocky shores could be explained by a set of meteo-oceanographic variables. The variables considered were salinity, sea surface temperature, photosynthetically active radiation, significant wave height and tidal range and were compiled from three different sources: remote sensing, reanalysis technique and in situ measurement. These variables were parameterized to represent average conditions (mean values), variability (standard deviation) and extreme events (minimum and maximum values). The results obtained in this study contribute to reinforce the EMBOS network approach and highlight the necessity of considering meteo-oceanographic variables in long-term assessments. The broad spatial distribution of pilot sites has allowed identification of latitudinal and longitudinal gradients manifested through species composition, diversity and dominance structure of intertidal macroalgae. These patterns follow a latitudinal gradient mainly explained by sea surface temperature, but also by photosynthetically active radiation, salinity and tidal range. Additionally, a longitudinal gradient was also detected and could be linked to wave height.
Understanding how changes in biodiversity can lead to changes in the functioning of ecosystems is a critical step for tracing the consequences of human activities through to impacts on ecosystem services. As defined and described in Chapter 1, it is widely recognised that the biodiversity of ecosystems can influence their functioning – the processing of energy and materials – and properties such as stability and total biomass. The relationship between biodiversity and ecosystem functioning has, however, been the subject of extensive and, at times, controversial research over the past two decades, the so-called BEF debate.
The BEF debate rose to prominence in ecology at a conference in Bayreuth in 1992 and has passed through several phases since then, in which the field has expanded in volume, scope, rigour and complexity (Naeem et al., 2009). The first major advances were made in terrestrial ecosystems, particularly grasslands (e.g. Naeem et al., 1994; Tilman et al., 1996). There was, initially, a lag in developing similar levels of understanding for marine ecosystems (Heip et al., 1998), but there is now a substantial body of work covering at least coastal ecosystems (Stachowicz et al., 2007; Naeem et al., 2009). Several authors have described how the structure and functioning of marine systems is different from that of terrestrial systems (e.g. Steele, 1985, 1991; Ormond, 1996; Stachowicz et al., 2007; Naeem, 2012), suggesting that understanding derived from terrestrial systems may not be applicable in a marine context. Indeed, a number of major syntheses have treated the systems separately (e.g. Balvanera et al., 2006; Cardinale et al., 2006). On the other hand, Schmid et al. (2009) argue that because their meta-analysis revealed no differences in the proportion of positive BEF relationships in marine versus terrestrial systems, there is no basis to argue that different mechanisms apply (and see Webb, 2012). An analysis by Crowe et al. (2012) reveals that in general BEF research in marine and terrestrial ecosystems has differed in spatial and temporal scale and approach, making it difficult to draw direct comparisons.
Marine ecosystems provide a range of essential benefits to society, including food and other products, waste assimilation, coastal protection and climate regulation as well as less tangible, but no less important cultural and aesthetic benefits (Chapter 2). To a considerable degree, those benefits are underpinned by ecosystem services dependent on the efficient functioning of the ecosystems, although detailed understanding of relationships between particular services and particular functional processes is currently being developed (Chapter 2). In turn, the efficient functioning of ecosystems has been linked to the number and identity of species present, as well as the prevailing environmental conditions (Chapter 5).
Society derives many of its benefits from ecosystems via sectoral activities and industries, such as fishing, construction, energy, shipping, leisure and tourism. These activities can impose pressures on ecosystems, such as removal of biomass, inputs of nutrients and other contaminants and the introduction of artificial structures and non-indigenous species (Chapter 3). Such pressures act through a range of mechanisms affecting different levels of biological organisation to modify biodiversity and ecosystem functioning (Chapters 3 and 4). The chapters in this book have reviewed current knowledge of how the spectrum of human activities and pressures (collectively referred to as stressors) affect biodiversity, ecosystem functioning and the provision of services and benefits to society. A key objective was to provide a synthesis of evidence for policy makers and managers to facilitate trade-offs between sectors of activity based on the benefits they provide weighed against the degree to which they may compromise the delivery of ecosystem services now and into the future (see Chapter 11).
In this chapter, we first synthesise and summarise the inferences presented in the book about the range of impacts of different activities and pressures on biodiversity and ecosystem processes. We then ask how this kind of knowledge can help policy makers and managers, particularly in the achievement of the international targets laid down in the Millennium Development Goals (Chapter 1) and whether the ecosystem approach and the concept of ecosystem services can provide an effective framework for facilitating the achievement of those goals.
The Earth is a blue planet. Seas and oceans cover over 70% of the Earth's surface and, with an average depth of over 3.2 km, the total volume of marine ecosystems is vastly greater than that of terrestrial and fresh-water environments combined, comprising 98% of the total inhabitable space on the planet (Speight and Henderson, 2010). Marine ecosystems contain 31 of the 33 phyla of animals, each of which constitutes a unique and distinctive body plan, with 15 of those phyla occurring only in the sea (Angel, 1993). Approximately 250 000 marine species have been described, with an estimated 750 000 still to be discovered (Census of Marine Life, 2010). Marine creatures include the largest ever to live (blue whales), yet the energy to fuel these giants is mainly captured by microscopic plankton, rather than more substantial plants, one of a number of fundamental differences between marine and terrestrial ecosystems (Steele, 1985, 1991; Webb, 2012). Of the global annual net primary productivity, approximately 104.9 petagrams (1015 grams) of carbon per year, around half is produced by marine ecosystems (Field et al., 1998). Although coral reefs and beds of seaweed are, per unit area, among the most diverse and productive ecosystems on Earth, open oceans have levels of productivity akin to terrestrial deserts because life is so thinly spread, but nevertheless make the single greatest contribution to global productivity because of their size (Whittaker and Likens, 1975).
Archaeological records show that even the earliest humans exploited the marine environment for food, as a medium for transportation and as a repository for waste (Jackson, 2001; Jackson et al., 2001). Today, the marine environment provides approximately 80 million tonnes per year of fish and shellfish from capture fisheries, representing about 3% of our global animal protein supply. Marine aquaculture contributes an additional 20 million tonnes (FAO, 2012). Therefore, marine ecosystems can be seen as having an important role in global food security (Frid and Paramor, 2012).
Ecosystem services are emerging as a key driver of conservation policy and environmental management. Delivery of ecosystem services depends on the efficient functioning of ecosystems, which in turn depends on biodiversity and environmental conditions. Many marine ecosystems are extremely productive and highly valued, but they are increasingly threatened by human activities. With contributions from leading researchers, this volume synthesises current understanding of the effects on biodiversity and ecosystem functioning caused by a variety of human activities and pressures at play in coastal marine ecosystems. The authors examine the likely consequences for ecosystem service provision, covering key topics including fisheries, aquaculture, physical structures, nutrients, chemical contaminants, marine debris and invasive species. Critically reviewing the latest developments, this is a unique resource both for environmental managers and policy-makers, and for researchers and students in marine ecology and environmental management.
To assess whether Mytilus edulis is selective in its secretion of byssus threads and entrapment of gastropods, experiments were conducted in laboratory aquaria and in the field. Exposure to dogwhelks (Nucella lapillus) or their effluent induced mussels to produce twice as many byssus threads as mussels exposed only to winkles (Littorina littorea) or those exposed only to seawater. There were no significant differences among treatments in the area over which byssus threads were secreted. Significantly more byssus threads were attached to the shells of dogwhelks than to winkles. Laboratory experiments produced broadly similar results to those in the field, but the level of response in the laboratory was greater. It is concluded that byssus threads were attached selectively to dogwhelks and that they may serve as a defence against predation.
Email your librarian or administrator to recommend adding this to your organisation's collection.