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Coastlines with extensive estuaries and broad tidal flats are acutely vulnerable to coastal development. The tidal wetlands of the Yellow Sea are globally important for waterbirds, yet river mouths have disproportionately been developed as industrial ports, fishing ports, or have become abandoned fishing ports, with the type of management strategies depending on biophysical attributes and regional economic drivers. However, river mouths also support extensive upper tidal flat ecosystems, in contrast to many open coastal regions of the Yellow Sea, where reclamation has excised many of the upper tidal flats and dramatically reduced the time that tidal flats are available for foraging and roosting waterbirds each day. However, the extent to which waterbirds disproportionately occurs in river mouths compared to the open coast in the region remains unclear. We used a paired survey design to quantify the waterbird communities and habitat attributes (i.e., areas of upper tidal flats, Spartina alterniflora, and human activity) of 15 river mouths and 15 otherwise similar adjacent open coasts areas along the Yellow Sea coast. Waterbird species richness and abundance were higher in river mouths than open coasts. Among river mouths, the most species rich waterbird communities occurred in fishing ports and the most species poor in industrial ports. Notably, upper tidal flats were absent in many of the open coast regions, which had been subject to reclamation. Our results suggest that river mouths, especially those river mouths currently used as fishing ports, are probably of crucial importance for waterbird conservation on the Jiangsu coast due to their larger areas of upper tidal flats. Our work highlights the need to ensure that the tidal flats in river mouth systems are effectively protected to promote the completion of the annual cycle of migratory waterbirds.

Land reclamation is a common strategy for coastal cities to expand their land territories. Although the marine environment degradation caused by land reclamation has been investigated in numerous studies, further exploration in terms of the spatial–temporal impacts of patterns and uses of reclaimed lands on the coastal environment is required to generate detailed policies for urban planning. Two-thirds of Macao’s territorial space has come from the ocean since the middle of the 19th century. Taking the land reclamation history in Macao from 1975 to 2018 as the empirical case, this study quantifies landscape metrics and uses of reclaimed lands through time, and further explores their impact on coastal water conditions by Granger causality tests, stepwise regression and land use regression across different spatial scales. Results show that landscape metrics have instant effects on the coastal water flow velocity and storm tide fluctuation, while various land uses are related to the coastal water turbidity and quality with a time lag length of two to three years after the land reclamation projects are completed. The strength of the relationship between land uses and coastal water conditions also depends upon spatial scales. The reclaimed land patterns with natural-like shorelines and ecological solutions in proximity to intensive coastal development are recommended to mitigate negative effects on coastal water conditions. Reasonable suggestions for efficient planning and management are provided in the findings that contribute to the environmentally friendly coastal development.

Bangladesh, a coastal developing nation with a diverse sustainable biodiversity of natural resources is currently focused upon by international communities as a result of its high potential of the coastal zone (CZ) with natural gas. Sustainable Coastal Zone Management (SCZM) is key to its national development. SCZM refers to the management of coastal resources in order to provide secure and alternative livelihoods, as well as to manage all types of coastal hazards and social and cultural well-being in order to ensure long-term productivity and minimize environmental impact. This paper aims to delineate the current initiatives and status of coastal management in Bangladesh, highlighting key issues such as climate changes, sea level rise, tropical cyclones, coastal and marine pollution, coastal erosions, saltwater intrusions, and mangrove degradations as well as the future trend in Bangladesh which will facilitate sustainable development by emphasizing the social, ecological, and economic pillars of sustainability. Unsustainable coastal development practices in Bangladesh are going to damage the coastal ecosystems, particularly mangrove forests and coral reefs, which provide protection against tropical cyclones caused by global climate change and coastal erosions. The paper concludes by outlining a roadmap toward achieving SCZM in Bangladesh. The road to achieving SCZM requires collaboration, integration of scientific research, policy frameworks, community engagement, capacity building, and long-term commitment from all stakeholders involved. So, it is required to address all kinds of coastal issues and reframes all existing coastal management practices to ensure a healthy productive ecosystem to achieve SCZM as well as the sustainable development of the country.

Sandy areas between rocky uplands, or natural pocket beaches, provide important habitat for coastal wildlife. On developed coasts, similar sandy areas, called urban pocket beaches, occur in the gaps between properties with coastal armoring (sea walls or revetments). These urban pocket beaches provide important nesting, foraging, and resting habitat for wildlife, particularly on extensively armored beaches. However, it is unclear if urban pocket beaches provide the same function as natural pocket beaches or offer benefits (e.g., reduced risk of inundation or erosion) lost at nearby armored areas. To address these knowledge gaps, we analyzed loggerhead marine turtle nesting patterns and reproductive success to determine if urban pocket beaches represent preferred nesting habitat along armored coastlines. We also determined if nests at urban pocket beaches are more likely than nearby armored and unarmored beaches to be inundated from wave runup, which could alter the incubation environment and nest productivity of marine turtles. The linear extent of urban pocket beaches in Florida was identified, then loggerhead marine turtle nesting success, nest density, and hatching success was compared between urban pocket beaches with armoring and beaches without armoring. We also modeled differences in wave runup exposure at these beaches under current conditions (2016–2019) without and with tropical storms and future (2060) intermediate-low and high sea level rise scenarios. Overall, pocket beaches account for less than 2% of Florida’s nesting beaches with higher abundance on more heavily armored shorelines. Nesting density in pocket beaches were similar to nearby beaches without armoring. However, female turtles were more likely to nest in urban pocket beaches compared to adjacent armored areas, and pocket beach nests had a higher hatchling success rate than unarmored and armored beaches. Our models suggest that exposure to wave runup varies by geographic location, but overall pocket beaches provided viable nesting habitat in all areas surveyed. Thus, managers should advocate for preserving urban pocket beaches on armored shorelines.

Natural and anthropogenic forces on Earth create changes in biophysical characteristics of landscapes in the forms of modifications or transformations. Since landscapes are composed of spatially configured patches of different land cover types, changes in the pattern composition and configuration may be used as indicators for identifying environmental trends and their underlying causes. To this end, pattern indices hold a strong potential to conceptualize landscape structure in many different ways. This study aims to analyse landscape changes in an urbanized coastal landscape in the eastern Mediterranean region of Turkey using pattern indices as development indicators. For this purpose, the spatial distribution of built-up areas was extracted for the years 1989, 1995, 2001, 2007 and 2019 using geo-referenced SPOT and Sentinel images. Eight landscape structure indices were calculated to demonstrate spatial and temporal diversity of area/edge, shape and aggregation characteristics of built-up patches. These indices are (1) class area (CA), (2) percentage of landscape (PL), (3) largest patch index (LPI), (4) edge density, (5) perimeter-area ratio (PARA), (6) fractal dimension (FRAC), (7) related circumscribing circle (RCC) and (8) percentage of like-adjacencies (PLADJ). The study area was divided into 215 grid-units to represent spatial diversity of development. The aforementioned indices were calculated separately for each of the units. The spatial distribution of built-up areas was also associated with land capability to assess land degradation trends. Results showed that much of the development occurred on Class I and II lands that are in fact prime agricultural areas. Results also suggest that the structure of building patches and the way that it changes vary between the coast and inland.

The coastal zone is typically highly developed and its ocean environment is vastly exposed to the onshore activities. Land-based pollution, as the "metabolite" of terrestrial human activities, significantly impacts the ocean environment. Although numerous studies have investigated these effects, few have quantified the interactions among land-human activity-ocean across both spatial and temporal scales. In this study, we have developed a land-human activity-ocean systemic framework integrating the coupling coordination degree model and tipping point to quantify the spatiotemporal dynamic interaction mechanism among the land-based pollution, human activities, and ocean environment in China from 2001 to 2020. Our findings revealed that the overall coupling coordination degree of the China's coastal zone increased by 36.9 % over last two decades. Furthermore, the effect of human activities on China's coastal environment remained within acceptable thresholds, as no universal tipping points for coastal pollution or ocean environment has been found over the 20-year period. Notably, the lag time for algal blooms, the key indicator of ocean environment health, was found to be 0-3 years in response to the land economic development and 0-4 years in response to land-based pollution. Based on the differences in spatiotemporal interactions among land-human activity-ocean system, we employed cluster analysis to categorize China's coastal provinces into four types and to develop appropriate management measures. Quantifying the interaction mechanism within the land-human activity-ocean system could aid decision-makers in creating sustainable coastal development strategies. This enables efficient use of land and ocean resources, supports coastal conservation and restoration efforts, and fosters effective management recommendations to enhance coastal sustainability and resilience., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Urban and green transitions require infrastructures that can cause pressure on coastal ecosystems. In northern Taiwan, plans to convert an oil-fired power plant to gas would necessitate a port terminal construction, threatening nearby corals and marine life. To mitigate construction impacts, the relocation of affected corals was proposed. We conducted a transplantation study, prior to such a large-scale coral relocation, to assess its feasibility and to identify potential risks associated with the marginal location of northern Taiwan for tropical corals. Five coral species, representative of the different ecological strategies, were selected. We used two methods (artificial frames and seabed cementation) to transplant 246 colony fragments to two pre-selected sites. Over a year, we monitored fragment survival and growth, in parallel with environmental conditions. We found that survival and growth were significantly influenced by transplantation methods, sites, and species. The difference between methods revealed biotic (predation by corallivorous snails) and abiotic (mechanical damage by waves) factors affecting coral survival and growth. Acropora species exhibited high growth, but also high mortality, consistent with their known ecology. Other species presented slower growth but higher survival. One site provided a better environment for corals, which we attributed to topography and reduced exposure. Overall, this study provides interesting insights into relocating corals in a high-latitude and urban coral ecosystem, highlighting risks related to mechanical damages and predation., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Vianney Denis reports financial support was provided by Taiwan Power Company., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

The North Atlantic Basin (NAB) has seen an increase in the frequency and intensity of tropical cyclones since the 1980s, with record-breaking seasons in 2017 and 2020. However, little is known about how coastal ecosystems, particularly mangroves in the Gulf of Mexico and the Caribbean, respond to these new "climate normals" at regional and subregional scales. Wind speed, rainfall, pre-cyclone forest height, and hydro-geomorphology are known to influence mangrove damage and recovery following cyclones in the NAB. However, previous studies have focused on local-scale responses and individual cyclonic events. Here, we analyze 25 years (1996-2020) of mangrove vulnerability (damage after a cyclone) and 24 years (1996-2019) of short-term resilience (recovery after damage) for the NAB and subregions, using multi-annual, remote sensing-derived databases. We used machine learning to characterize the influence of 22 potential variables on mangrove responses, including human development and long-term climate trends. Our results document variability in the rates and drivers of mangrove vulnerability and resilience, highlighting hotspots of cyclone impacts, mangrove damage, and loss of resilience. Cyclone characteristics mainly drove vulnerability at the regional level. In contrast, resilience was driven by site-specific conditions, including long-term climate trends, pre-cyclone forest structure, soil organic carbon stock, and coastal development (i.e., proximity to human infrastructure). Coastal development is associated with both vulnerability and resilience at the subregional level. Further, we highlight that loss of resilience occurs mostly in areas experiencing long-term drought across the NAB. The impacts of increasing cyclone activity on mangroves and their coastal protection service must be framed in the context of compound climate change effects and continued coastal development. Our work offers descriptive and spatial information to support the restoration and adaptive management of NAB mangroves, which need adequate health, structure, and density to protect coasts and serve as Nature-based Solutions against climate change and extreme weather events., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

Artificial structures often support depauperate communities compared to natural rocky shores. Understanding variation in ecological success across shore types, particularly regarding habitat-forming species or those with structuring roles, is important to determine how artificial structure proliferation may influence ecosystem functioning and services. We investigated the population structure, sex ratio and reproductive potential of limpets on natural shores and artificial structures on Irish Sea coasts. Limpets were generally less abundant and Patella vulgata populations were often male dominated on artificial structures compared to natural shores, suggesting that shore type may influence these factors. P. vulgata length varied across sites within the Irish Sea (nested in coast and shore type) in autumn/winter, as well as temporally across sites along the Welsh coast. There was no difference in the proportion of P. vulgata in advanced stages of gonad development across shore types. The results suggest that rip-rap artificial structures may provide a habitat comparable to natural shores, however, the addition of ecological engineering interventions on artificial structures may allow limpet populations to better approximate those on natural shores., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: All authors reports financial support was provided by European Regional Development Fund., (Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Kelp habitats contribute to marine productivity and diversity, making understanding the constraints on their distribution important. In the Gulf of St. Lawrence, Alaria esculenta occupies a subset of Saccharina latissima's range. Since tolerance to sedimentation by early life stages was suggested to cause this contrasting distribution, we tested the influence of sediment levels on spore attachment and development. For both species, the proportion of attached spores that developed decreased with increasing sediment. However, spore attachment and gametophyte density increased with sediment concentration but only for Saccharina. At the maximum sediment level examined, spore attachment and gametophyte densities of the two species were similar, contrary to the idea that sediment effects on early life stages explain differences in adult distribution. Further investigation, particularly with higher sediment loads, is required to confirm this conclusion. As turbidity is increasing globally, understanding the mechanisms underpinning changes in seaweed distribution will facilitate appropriate local-scale management., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

In the face of increasing anthropogenic threats, coastal nations need to reach common ground for effective marine conservation. Understanding species' connectivity can reveal how nations share resources, demonstrating the need for cooperative protection efforts. Unfortunately, connectivity information is rarely integrated into the design of marine protected areas (MPAs). This is exemplified in the Red Sea where biodiversity is only nominally protected by a non-cohesive network of small-sized MPAs, most of which are barely implemented. Here, we showcase the potential of using connectivity patterns of flagship species to consolidate conservation efforts in the Red Sea. We argue that a large-scale MPA (LSMPA) would more effectively preserve Red Sea species' multinational migration routes. A connectivity-informed LSMPA approach provides thus one avenue to unite coastal nations toward acting for the common good of conservation and reverse the global decline in marine biodiversity., (Copyright © 2021 The Authors. Published by Elsevier Ltd.. All rights reserved.)

This study evaluates the potential area and the key environmental factors supporting Sargassum bed restoration (SBR) in the highly turbid northwestern Arabian Gulf where rapid coastal development impinges on the marine ecosystem functioning. Water depth was a primary environmental factor governing the distribution of the subtidal macroalgae beds in these turbid waters. The relationship between Sargassum coverage and water depth measured by an echo sounder indicated optimal water depths where the maximum coverage was observed. The availability of stable hard substrate was another key factor introducing heterogeneity in Sargassum coverage. Potential area for the SBR estimated based on the optimal depths was 4.26 km 2 , whereas only 50% of the potential area (2.19 km 2 ) was currently vegetated due to the absence of hard substrate. The outcomes of this study offer beneficial information toward implementation of the SBR as a part of mitigation measures in future coastal development plans in the region., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

The coastlines of many Arabian cities are now dominated by structures such as seawalls, breakwaters and jetties as urbanization has expanded rapidly in the region. Coastal development has substantially degraded the mangrove forests, saltmarshes, seagrass meadows, oyster beds and coral reefs that traditionally provided invaluable ecosystem goods and services to coastal trading villages of the Arabian Gulf. Regional awareness of environmental issues is growing, however, and local governments are increasingly promoting more sustainable urban development. The use of ecological engineering approaches, along with improved environmental policies, may mitigate some past impacts, and will potentially create new development projects with greater ecological benefits for more sustainable growth in the future. In this paper, we discuss past coastal development in the Gulf, and offer advice on how ecological engineering could be used to enhance the ecological benefits of coastal infrastructure, particularly by encouraging the colonization of juvenile corals and fishes. Such approaches can encourage more sustainable development of this increasingly urbanized seascape., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

As long-lived apex predators in the Pearl River Estuary (PRE) of China, Indo-Pacific humpback dolphins (Sousa chinensis) are particularly vulnerable to anthropogenic impact and may undergo considerable ecological trait changes. The variability of traits, however, is often difficult to trace back in nature. Here, we analyzed stable isotope ratios of carbon and nitrogen in muscle samples of 88 S. chinensis stranded in the PRE from 2004 to 2016 to investigate the ecological changes occurring in the dolphins. Stable isotope analysis revealed the existence of two sub-aggregations of S. chinensis in the PRE. Generalized additive models showed significant decreasing trends in both carbon and nitrogen isotopic signatures over time, indicating the habitat changes and dietary shifts, possibly due to the influence of increased coastal developments and fishing activities in the PRE. Diet modeling suggests that the proportional contribution of higher trophic-level prey decreased in the S. chinensis diet over time, while increased consumption of lower trophic-level prey was observed. This shift was related to depletion of higher trophic-level prey caused by overfishing. Although S. chinensis could temporarily compensate for the lost energy supply through feeding plasticity (revealed by the negligible differences of isotope niche width among different stranding periods), long-term depletion in prey availability may cause long-lasting negative effects on this dolphin population. This study highlights the crucial relationships between fishery management and dolphin conservation, providing scientific evidence for the long-term protection of this threatened species in the PRE region., (Copyright © 2018 Elsevier B.V. All rights reserved.)

It is well established that anthropogenic nutrient inputs harm estuarine seagrasses, but the influence of nutrients in rocky intertidal ecosystems is less clear. In this study, we investigated the effect of anthropogenic nutrient loading on Phyllospadix spp., a rocky intertidal seagrass, at local and regional scales. At sites along California, Washington, and Oregon, we demonstrated a significant, negative correlation of urban development and Phyllospadix bed thickness. These results were echoed locally along an urban gradient on the central California coast, where Phyllospadix shoot δ 15 N was negatively associated with Phyllospadix bed thickness, and experimentally, where nutrient additions in mesocosms reduced Phyllospadix shoot formation and increased epiphytic cover on Phyllospadix shoots. These findings provide evidence that coastal development can threaten rocky intertidal seagrasses through increased epiphytism. Considering that seagrasses provide vital ecosystem services, mitigating eutrophication and other factors associated with development in the rocky intertidal coastal zone should be a management priority., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Over the past decade, development along the northern coast of Jamaica has accelerated, resulting in elevated levels of sedimentation on adjacent reefs. To understand the effects of this development on sponge community dynamics, we conducted surveys at three locations with varying degrees of adjacent coastal development to quantify species richness, abundance and diversity at two depths (8-10 m and 15-18 m). Sediment accumulation rate, total suspended solids and other water quality parameters were also quantified. The sponge community at the location with the least coastal development and anthropogenic influence was often significantly different from the other two locations, and exhibited higher sponge abundance, richness, and diversity. Sponge community composition and size distribution were statistically different among locations. This study provides correlative evidence that coastal development affects aspects of sponge community ecology, although the precise mechanisms are still unclear., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Anthropogenically enhanced delivery of sediments and other land-based sources of pollution represent well-recognized threats to nearshore coral reef communities worldwide. Land cover change is commonly used as a proxy to document human-induced alterations to sediment and pollutant delivery rates to coral reef bearing waters. In this article, land cover change was assessed for a 69-km(2) watershed in Puerto Rico between 1936 and 2004 by aerial photograph interpretation. Forests and sugar cane fields predominated from 1936 through the late 1970s, but while cropland dipped to negligible levels by 2004, net forest cover doubled and built-up areas increased tenfold. The watershed-scale land cover changes documented here mimicked those of the entire Puerto Rican landmass. Sediment yield predictions that rely on the sort of land cover changes reported here inevitably result in declining trends, but anecdotal and scientific evidence in the study watershed and throughout Puerto Rico suggests that sediment and pollutant loading rates still remain high and at potentially threatening levels. The simultaneous reduction in living coral cover that accompanied reforestation and urbanization patterns since the 1970s in our study region is discussed here within the context of the following non-mutually exclusive potential explanations: (a) the inability of land cover change-based assessments to discern spatially-focused, yet highly influential sources of sediment; (b) the potentially secondary role of cropland and forest cover changes in influencing nearshore coral reef conditions relative to other types of stressors like those related to climate change; and (c) the potentially dominant role that urban development may have had in altering marine water quality to the extent of reducing live coral cover. Since identification of the causes for coral reef degradation has proven elusive here and elsewhere, we infer that coral reef management may only be effective when numerous land- and marine-based stressors are simultaneously mitigated., (Copyright © 2014 Elsevier B.V. All rights reserved.)