The article discusses the possibility and perspectives of using the reclaimed artificial areas in the coastal zone of marine estuaries for the sustainable development of urban infrastructure and creation of modern architectural ensembles with the background of green economy using the example of Lakhta-Center on the northern coast of the Neva Bay (St. Petersburg, Russia). The geo-ecological stability of underwater and coastal landscapes of the coastal zone of the Neva Bay is analyzed using side scan sonar. The environmental sensitivity of coastal ecosystems is estimated. The received data can be used on practice for planning the construction work and for the development of the infrastructure of urbanized coastal zone of the Neva Bay. The general geo-ecological situation in the observed area is rather stable. The coastal zone has good perspectives for the development of a sustainable urban infrastructure against the backdrop of the green economy. The special attention should be paid to migration of birds and fish, who are using the North Lakhta coast as a temporary refugium during Spring and Autumn migrations. An effective solution from both environmental and economic points of view could be the organization of the Nature Conservation Reserve, which is spatially associated with the Lakhta Center zone. Such type of the complex using of the coastal zone could be a good example of the spatial planning in the environmentally sensitive area.
Eco-engineering and the installation of green infrastructure such as artificial floating islands (AFIs), are novel techniques used to support biodiversity. The European Convention on Biological Diversity highlighted the development of green infrastructure as a key method of enhancement in degraded habitats. Research specifically on AFIs in marine environments has largely focused on their ecological functioning role and engineering outcomes, with little consideration for the social benefits or concerns. The aim of this study was to gain an understanding of public perception of coastal habitat loss in the UK and AFIs as a method of habitat creation in coastal environments. This was achieved via a survey, consisting of six closed and two open questions. Of the 200 respondents, 94.5% were concerned about the loss of coastal habitats in the UK, but less than a third were aware of habitat restoration or creation projects in their area of residence. There was a positive correlation between proximity of residency to the coast and knowledge of habitat restoration or creation projects. The majority of the respondents understood the ecological functioning role of AFIs and 62% would preferably want successful plant growth and avian species utilising the AFI. Nearly a third of the respondents had concerns about AFI installations, such as the degradation of the plastic matrix, long term maintenance and disturbance of native species. Despite 90.9% of the respondents supporting the installation of AFIs, the concerns of the public must be addressed during the planning stages of any habitat creation project.
A major goal of ecology is to understand how spatial heterogeneity determines patterns of species diversity and composition. Studies have demonstrated positive relationship between environmental heterogeneity and diversity, but evidence from marine ecosystems is controversial and scarce in terms of how spatial heterogeneity and diel period mediate this relationship. We used fish communities from four Southwestern Atlantic vessel reefs to assess whether positive heterogeneity-diversity relationships (HDR) hold for these mobile organisms and whether the relationships weaken with nightfall. We sampled fishes in three habitats of contrasting structural complexity (high, low and control), over day and night, and employed two complementary diversity frameworks: partitioning of gamma diversity into independent alpha and beta components (Jost's approach) and partitioning of beta diversity into turnover and nestedness components (Baselga's approach). We recorded 5005 fishes belonging to 76 species and 31 families. As expected, the mean alpha diversity of rare species (0D) doubled from control to high complexity areas and decreased by half from day to night. The diversity of typical species (1D) also doubled from control to high complexity areas, but did not reduce at night. Complexity and diel period did not have significant effect on the diversity of dominant species (2D). No relationship between complexity and alpha diversity was weakened at night. Beta diversity of the three diversity orders significantly differed from 1 (totally homogeneous vessel reef), indicating that complexity underlies patterns of beta diversity. This effect was consistent in both diel periods, contradicting expectations of weaker influence of complexity at night. The turnover component of beta diversity was consistently greater than nestedness at day and nigth (2.8 and 1.9-fold, respectively). Our findings support positive HDR for the diversity of rare and typical species. Dominant species also respond to heterogeneity by replacing each other across the complexity gradient, but not by becoming more numerous in high complexity areas. Diel changes did not affect the strenght of HDR, revealing an uninterrupted role of environmental heterogenity on fish communities. Conserving heterogeneous, structurally complex habitats is crucial for conserving marine fish diversity.
Reef fish resources provide numerous ecosystem services in the northern Gulf of Mexico (nGOM) large marine ecosystem. Artificial reefs (ARs) have been distributed across the nGOM in attempts to enhance reef fish habitat and increase fishery productivity, but few data exist to distinguish ecological from fishery functions of ARs compared to natural reefs (NRs), particularly at the regional scale. Therefore, we conducted remotely operated vehicle surveys of reef fish communities at 47 reef sites within a ∼20,000 km2 area of the nGOM shelf and tested the effect of reef type (NR versus AR), depth (≤35 or >35 m), relief (≤2 m or >2 m), and complexity (low or high) on fish diversity and community structure as well as trophic guild- and species-specific densities. Twenty-one species were present at >20%, nine at >50%, and three at >75% of study reefs. Fishery species (i.e., Lutjanus campechanus, Seriola dumerili, and Rhomboplites aurorubens) and invasive Pterois volitans were frequently observed (>50% of sites) or numerically dominant, especially at ARs. Main effects did not significantly affect the presence of specific species or trophic guilds, but interactions among factors significantly affected species- and trophic guild-specific densities. Our results indicate that effects of habitat characteristics on fish communities are more nuanced than previously described. Fish communities are moderately similar at the majority of sites but specific habitat characteristics can interact to dramatically affect densities of some species, particularly those that depend on complex structures for refuge. Simple ARs tend to concentrate high densities of a few important fishery species with low densities of other small demersal reef fishes. Complex NRs with high relief also support high densities of planktivorous fishery species but greatly increase densities of small, demersal, non-fishery species that directly utilize complex reef structure for refuge.
Considering the visibility of infrastructural projects as a means of coastal protection against urban sea level change, this paper draws attention to dyking as both a form of ‘defense’ and as a means of ‘dwelling’ or living with/from water. By tracing the emergence of a recent donor-funded polder dyke in Metro Manila (Philippines), the paper focuses on the infrastructural politics of coastal protection in a delta megacity, often technocratically framed as a global disaster capital. It illustrates how, as a socio-technological object, a dyke might serve as a distinct mode of governing everyday life along high density urban coastlines. Combining insights from Evolutionary Governance Theory (EGT) and infrastructural anthropology, the paper traces the materialization of the dyke as an evolving ‘living’ infrastructure, placing it against a broader canvas of urban transformations encompassing contestations around disaster risk reduction, land use, uneven livelihood access, tenurial rights, and neoliberal aesthetics. As a means of transcending the defense/dwelling binary, a typology of four interrelated frames are presented with which to trace localised meanings and practices of dyking as a mode of everyday governance, namely as: a) a line of defence for protective living; b) urban spectacle; c) a buffer zone or marker for land acquisition and; d) a fluid borderland, which at times ruptures the very material fixities and aqua-terrestrial distinctions upon which hard engineering infrastructural solutions are often premised.
Offshore oil and gas platforms are found on continental shelves throughout the world’s oceans. Over the course of their decades-long life-spans, these platforms become ecologically important artificial reefs, supporting a variety of marine life. When offshore platforms are no longer active they are decommissioned, which usually requires the removal of the entire platform from the marine environment, destroying the artificial reef that has been created and potentially resulting in the loss of important ecosystem services. While some countries allow for these platforms to be converted into artificial reefs under Rigs-to-Reefs programs, they face significant resistance from various stakeholders. The presence of offshore platforms and the associated marine life alters the ecosystem from that which existed prior to the installation of the platform, and there may be factors which make restoration of the ecosystem unfeasible or even detrimental to the environment. In these cases, a novel ecosystem has emerged with potentially significant ecological value. In restoration ecology, ecosystems altered in this way can be classified and managed using the novel ecosystems concept, which recognizes the value of the new ecosystem functions and services and allows for the ecosystem to be managed in its novel state, instead of being restored. Offshore platforms can be assessed under the novel ecosystems concept using existing decommissioning decision analysis models as a base. With thousands of platforms to be decommissioned around the world in coming decades, the novel ecosystems concept provides a mechanism for recognizing the ecological role played by offshore platforms.
The replacement of natural marine habitats with less structurally complex human infrastructure has been linked to the homogenisation of epibenthic assemblages and associated changes in fish assemblages. To mitigate these impacts, eco-engineering efforts have focussed on increasing the physical and biogenic complexity of artificial structures, in the form of crevices added to seawalls and the seeding of the substrate with habitat-forming organisms such as oysters. While these studies have assessed how these interventions affect epibenthic assemblages, the effect of these strategies on the behaviour, such as feeding and habitat use, of different functional groups of fish (e.g. cryptobenthic and pelagic) remains uncertain. To do this, we manipulated complexity on seawalls by adding concrete tiles with different physical (flat or structured with crevices and ridges) and biogenic (seeding with two common habitat-forming species or naturally recruited fouling) complexities. We assessed pelagic and cryptobenthic fish species composition, abundance, interaction time with the tiles and number of feeding bites on three occasions 8–12 months after deployment. Cryptobenthic fish interacted more with physically complex tiles than flat tiles, regardless of biogenic complexity. In contrast, cryptobenthic fish fed more from flat tiles compared to physically complex tiles, and also appeared to feed more from tiles seeded with oysters. Pelagic fish interacted and fed more from naturally fouled tiles compared to unfouled control tiles, regardless of physical complexity. This study showed that manipulating complexity at the scales used here affects behaviour of fish, but it does not affect fish community. Increasing physical complexity facilitated fish use of seawalls as habitat by providing refuge, while it also hindered fish feeding by providing refuge for their prey. Cryptobenthic fish are important trophic linkages in their ecosystems and we have shown that by changing habitat complexity, we can change the habitat use and feeding activity of these fish, allowing them to fulfil this essential ecosystem role.
We argue that there is a separation between studies of the biophysics of natural and “built” marine canopies. Here, by “built” we specifically refer to floating, suspended aquaculture canopies. These structures, combining support infrastructure and crop, exhibit several unique features relative to natural marine canopies, in that they take a particular species, suspend them in spatially structured, mono-cultured arrangement and then induce a systematic harvest cycle. This is in contrast to natural canopies that are irregular and variable in form, have natural recruitment and growth, and sustain some level of biodiversity and more exposed to climate extremes. We synthesize published work to identify the points of difference and similarity with natural canopy studies. This perspective article identifies four main themes relating to (i) key scales, (ii) structural configuration, (iii) connections between biology and physics and (iv) connecting natural and built canopy science. Despite clear differences between natural and built canopies, they have more in common than not and we suggest that both sub-fields would benefit from better connection across the divide.
Over the last decade there has been a global effort to eco-engineer urban artificial shorelines with the aim of increasing their biodiversity and extending their conservation value. One of the most common and viable eco-engineering approaches on seawalls is to use enhancement features that increase habitat structural complexity, including concrete tiles molded with complex designs and precast “flowerpots” that create artificial rock pools. Increases in species diversity in pits and pools due to microhabitat conditions (water retention, shade, protection from waves, and/or biotic refugia) are often reported, but these results can be confounded by differences in the surface area sampled. In this study, we fabricated three tile types (n = 10): covered tile (grooved tile with a cover to retain water), uncovered tile (same grooved tile but without a cover) and granite control. We tested the effects of these tile types on species richness (S), total individual abundance (N), and community composition. All tiles were installed at 0.5 m above chart datum along seawalls surrounding two island sites (Pulau Hantu and Kusu Island) south of Singapore mainland. The colonizing assemblages were sampled after 8 months. Consistent with previous studies, mean S was significantly greater on covered tiles compared to the uncovered and granite tiles. While it is implied in much of the eco-engineering literature that this pattern results from greater niche availability allotted by microhabitat conditions, we further investigated whether there was an underlying species-individual relationship to determine whether increases in S could have simply resulted from covered tiles supporting greater N (i.e., increasing the probability of detecting more species despite a constant area). The species-individual relationship was positive, suggesting that multiple mechanisms are at play, and that biodiversity enhancements may in some instances operate simply by increasing the abundance of individuals, even when microhabitat availability is unchanged. This finding underscores the importance of testing mechanisms in eco-engineering studies and highlights ongoing mechanistic uncertainties that should be addressed to inform the design of more biodiverse seawalls and urban marine environments.
Seawater desalination is increasingly being pursued to address freshwater shortages. In California, multiple coastal seawater desalination facilities have been proposed to diversify water portfolios and to increase reliability of water supply. This paper explores local residents support for a newly constructed desalination plant in Carlsbad, a small coastal community in Southern California. The plant is the first high-capacity desalination facility in California and started operation in December 2015. We found strong support for the desalination plant as 71.9% of residents reported support for the plant. Only 15.5% of respondents were undecided indicating that residents had a clear opinion on the plant. Perceptions about local water resources were significant predictors of support. Attitudes may change over time if the state of water resources and perceptions thereof change. Expected outcomes of the plant also predicted support. An increase in available drinking water was a positive predictor, while environmental and social impacts were negative predictors. Economic impacts in terms of an increase in the price of water did not influence local support. Ethnicity and age were the only socio-demographic variables that had an effect on support suggesting that the socio-demographic profile of a community may not be a good predictor of community support or rejection of this water supply technology.