Continental Coast Research Articles

Economic feasibility of floating offshore wind farms in Portugal

The objective of this article is to apply a method to determine the economic feasibility of floating offshore wind farms at Portugal continental coast. The method proposed has several phases: geographic, economic and restrictions. The objective of the geographic phase is to estimate the input variables that will be afterwards used to calculate the economic parameters in the economic phase. The restriction of bathymetry, the last stage, is then added to the economic maps previously calculated, whose value will be different depending on the floating offshore wind device chosen. In this study, two scenarios for electric tariff have been taken into consideration as well several floating offshore wind substructures: semisubmersible, TLP and spar. Results indicate what is the best floating offshore wind platform in terms of economic parameters and where is the best area, in the study region, to implement floating offshore wind farms.

Toxin profile of Ostreopsis cf. ovata from Portuguese continental coast and Selvagens Islands (Madeira, Portugal)

The toxigenic dinoflagellate Ostreopsis cf. ovata is known to produce a range of palytoxin (PLTX) - related compounds named ovatoxins (OVTX). O. cf. ovata presents a wide variability in toxin production and its toxic profile is strain-specific. Several OVTXs, denominated from -a to -h and -l have been reported from different strains of this benthic microalgae up to now, mainly in Mediterranean isolates. However, less is known about the toxin profile of the strains present in the Atlantic coasts of Europe. In this work, strains of O. cf. ovata isolated from the South coast of Portugal mainland (Algarve) and Selvagens Island (Madeira, Portugal) were cultured and tested for toxicity by hemolytic assay. Toxin profiles were qualitatively elucidated by Liquid Chromatography-High Resolution Mass Spectrometry (LC-HRMS). The strain from Algarve presented lower toxic potency than the strain from Selvagens island (12.3 against 54.8 pg of PLTX equivalents per cell) showing in both cases the characteristic toxin profile of Mediterranean strains. The major component, OVTX-a, was concomitant with OVTX from -b to -g and isobaric PLTX. Regarding the morphological characteristics of these strains, as well as their toxin fingerprint, it is likely they are closely related to strains from Mediterranean coasts. The present study reports for the first time the occurrence of several OVTX congeners and iso-PLTX in O. cf. ovata from Portuguese waters. This study provides valuable information to characterize the risk of OVTXs-related outbreaks in Portugal.

Coral fracture by derelict fishing gear affects the sustainability of the marginal reefs of Ecuador

Hard coral coverage contributes to increasing the structural complexity of coral reefs, provides biological resources and drives biological and ecological interactions among reef organisms. Declines in the structural complexity and coral diversity of tropical reefs, due to the influence of anthropogenic activities, have been reported around the world in recent decades; however, coral reefs on the continental coast of Ecuador have been poorly studied. From September 2017 to April 2018, the method of permanent belt transects and quadrats was used to assess the status of coral (percentage of live, dead and fractured coral) to determine the contribution of derelict fishing gear to the process of coral fracture, which causes loss of structural complexity on two marginal coral-rocky reefs in the central coast of Manabi-Ecuador: Perpetuo Socorro and Ureles. Three geomorphological zones [crest (5–7 m depth), slope (7–10 m depth) and bottom (10–13 m depth)] were assessed. Results show that the crest zone in Ureles reef was highly affected by the entanglement of nets compared with Perpetuo Socorro, and identify derelict fishing gear as a key driver in the process of the fracturing and fragmentation of coral. Seasonal and site-associated factors also had a significant effect on the structural complexity of the reef studied. Destruction of coral in the crest zones drastically affects invertebrate and fish communities. We recommend a periodical assessment to measure the loss of structural complexity plus the implementation of a recovery program for the reefs studied that involves the education, active participation and collaboration of artisanal fishermen, governmental organizations and universities.

Where Marine Protected Areas would best represent 30% of ocean biodiversity

The IUCN (the International Union for Conservation of Nature) World Conservation Congress called for the full protection of 30% of each marine habitat globally and at least 30% of all the ocean. Thus, we quantitatively prioritized the top 30% areas for Marine Protected Areas (MPAs) globally using global scale measures of biodiversity from the species to ecosystem level. The analysis used (a) Ecosystems mapped based on 20 environmental variables, (b) four Biomes (seagrass, kelp, mangrove, and shallow water coral reefs) plus seabed rugosity as a proxy for habitat, and (c) species richness within each biogeographic Realm (indicating areas of species endemicity), so as to maximise representivity of biodiversity overall.We found that the 30% prioritized areas were mainly on continental coasts, island arcs, oceanic islands, the southwest Indian Ridge, the northern Mid-Atlantic Ridge, the Coral Triangle, Caribbean Sea, and Arctic Archipelago. They generally covered 30% of the Ecosystems and over 80% of the Biomes. Although 58% of the areas were within countries Exclusive Economic Zones (EEZ), only 10% were in MPAs, and <1% in no-take MPAs (IUCN category Ia). These prioritized areas indicate where it would be optimal to locate MPAs for recovery of marine biodiversity within and outside country's EEZ. Our results thus provide a map that will aid both national and international planning of where to protect marine biodiversity as a whole.

Independent evolutionary lineage of the clingfish Gobiesox adustus (Gobiesocidae) from Isla del Coco, Costa Rica

Introduction: Isla del Coco is an important protected area for marine fauna in the Eastern Tropical Pacific. In this area, the species that inhabit the intertidal zone have been subject to few studies. One of the species inhabiting these areas is the clingfish Gobiesox adustus (Gobiesocidae). Objective: To analyze for the first time the mitochondrial gene cytochrome oxidase subunit 1 (cox1) of G. adustus’ population from Isla del Coco and compare it with those of continental coast of Costa Rica and Ecuador. Methods: We constructed a haplotype network for these samples. Genetic diversity, distance and structure were calculated by several software. The historical demography of Isla del Coco samples was assessed with the method Bayesian skyline plot as implemented in BEAST2. Results: The samples segregate into three haplogroups: one consisting of the Isla del Coco samples, a second consisting of a subset of the Ecuador samples, and a third consisting of Costa Rica and the remaining Ecuador samples. The genetic distances between the three haplogroups range between 1.6% and 2.1% (uncorrected p-distance), and pairwise ΦST and AMOVA results between the three haplogroups show high and significant values. Conclusions: The Isla del Coco haplogroup showed a Pleistocene population growth, which agrees with demographic patterns found in other marine organisms. The history of isolation of the G. adustus population from Isla del Coco demonstrates the evolutionary independence of this population.

Spatial distribution and abundance of the by‐catch coastal elasmobranch Raja undulata: Managing a fishery after moratorium

AbstractThe undulate ray Raja undulata Lacepède is a coastal species common along the north‐eastern Atlantic Ocean and Mediterranean Sea and is highly accessible to coastal fisheries. Between 2009 and 2015, the species was under a European Union (EU) fisheries moratorium that hampered the collection of data to assess its stock status in Portuguese waters. After that period, a small experimental EU fishing quota was set for Portugal enabling collection of fishery data under a fishermen self‐sampling scenario. Based on the data collected, R. undulata abundance was estimated along the Portuguese continental coast through the application of a N‐mixture model and incorporating environmental factors. The results support the species coastal and patchy nature across the study area with higher abundances estimated in areas associated with shallow sandy bottoms as the Southwest region. The present work constitutes an important step for the management of this fishery resource, in particular concerns about its abundance trends over time and its spatial distribution and habitat requirements.

Population Genetic Structure is Unrelated to Shell Shape, Thickness and Organic Content in European Populations of the Soft-Shell Clam Mya Arenaria.

The soft-shell clam Mya arenaria is one of the most ancient invaders of European coasts and is present in many coastal ecosystems, yet little is known about its genetic structure in Europe. We collected 266 samples spanning a latitudinal cline from the Mediterranean to the North Sea and genotyped them at 12 microsatellite loci. In parallel, geometric morphometric analysis of shell outlines was used to test for associations between shell shape, latitude and genotype, and for a selection of shells we measured the thickness and organic content of the granular prismatic (PR), the crossed-lamellar (CL) and the complex crossed-lamellar (CCL) layers. Strong population structure was detected, with Bayesian cluster analysis identifying four groups located in the Mediterranean, Celtic Sea, along the continental coast of the North Sea and in Scotland. Multivariate analysis of shell shape uncovered a significant effect of collection site but no associations with any other variables. Shell thickness did not vary significantly with either latitude or genotype, although PR thickness and calcification were positively associated with latitude, while CCL thickness showed a negative association. Our study provides new insights into the population structure of this species and sheds light on factors influencing shell shape, thickness and microstructure.

On the dynamics in the southeastern Ligurian Sea in summer 2010

Drifters and a glider were operated in the southeastern Ligurian Sea to study the near-surface currents and water mass properties in summer 2010. Additional data were collected by a moored current meter in the Corsica Channel (CC). These in situ data were complemented by surface wind products, satellite images of ocean color and a Regional Ocean Modeling System (ROMS) numerical model that was implemented to simulate the local coastal dynamics. Southward currents were prevailing along the continental Italian coast, advecting filaments with a high optical signal coming from the Arno River. North of Elba Island, currents turned westward and northward in the vicinity of the CC. Further to the north they veered eastward, forming an anticyclonic circulation feature centered around Capraia Island. This general circulation picture was disrupted and reversed during events of sustained southerly winds occurring with a period of about a week. The near-surface currents in the CC and the anticyclonic circulation around Capraia Island showed the same weekly variations related to the local wind forcing. The ROMS model simulations agreed satisfactorily with the observations, in particular the strength of the Capraia anticyclonic circulation (quantified with the Capraia index) was confirmed to be strongly wind-dependent.

Data mining approach to shipping route characterization and anomaly detection based on AIS data

A data mining approach is presented for probabilistic characterization of maritime traffic and anomaly detection. The approach automatically groups historical traffic data provided by the Automatic Identification System in terms of ship types, sizes, final destinations and other characteristics that influence the maritime traffic patterns off the continental coast of Portugal. The approach consists of identifying relevant waypoints along a route where significant changes in the ships’ navigational behaviour are observed, such as changes in heading, using trajectory compression and clustering algorithms. This provides a vector-based representation of the ship routes consisting of straight legs and connecting turning sections that facilitates route probabilistic characterization and anomaly detection. The maritime traffic is characterized probabilistically at the identified route legs and waypoints in terms of lateral distribution of the trajectories and speed profile, which allows the characterization of the typical behaviour of a group of similar ships along a particular route. In the proposed approach heading changes are automatically detected using the Douglas and Peucker algorithm and clustered by the density-based spatial clustering of applications with noise algorithm. The proposed method is applied to the characterization of southbound maritime traffic from the traffic separation scheme off Cape Roca to the ports of Lisbon, Setúbal and Sines. Finally, an example of ship trajectory anomaly detection based on the developed maritime traffic probabilistic models is provided.

An Integrated Coastal Sediment Management Plan: The Example of the Tuscany Region (Italy)

This paper presents the results of a study carried out to support the Region of Tuscany Coastal Sediment Management Plan, with the main aim of establishing the sediment budget considering the time span from 1981–1985 to 2005 for the 56 coastal sectors into which the 215 km-long continental sandy coast of Tuscany (Italy) was divided. The sand stability (according to a stability index) and colour compatibility (according to the CIEL*a*b* colour space with an acceptability range conforming to national guidelines) were determined in order to assess the possibility of using the available sediment in accreting sectors to nourish the beach in eroding areas. Only in two cases—i.e., the updrift of a harbour (at Viareggio) and in a convergence zone (at Marina di Pietrasanta)—are the volumes of sufficient magnitude to support a large nourishment project; however, the mean sand size is too small to guarantee efficient nourishment, even with medium-term stability. In contrast, the colour difference, in most of the cases, was shown to be acceptable. Other small sediment stocks, suitable for colour but not for grain size, can be used for periodic ephemeral nourishment works to support seasonal tourist activities. The limited resources available make it necessary to adopt a plan for their optimal use from a regional perspective. This kind of study is of great interest for the proposal of sound management actions to counteract the increasing erosion processes linked to climate change phenomena and human effects on rivers and coastal systems.

Green turtle mitochondrial microsatellites indicate finer-scale natal homing to isolated islands than to continental nesting sites

In highly mobile philopatric species, defining the scale of natal homing is fundamental to characterizing population dynamics and effectively managing distinct populations. Genetic tools have provided evidence of regional natal philopatry in marine turtles, but extensive sharing of maternally inherited mitochondrial control region (CR) haplotypes within regions (&lt;500 km) often impedes identification of population boundaries. Previous CR-based analyses of Florida (USA) green turtleChelonia mydasnesting sites detected at least 2 populations, but the ubiquity of haplotype CM-A3.1 among southern rookeries decreased the power to detect differentiation. We reassessed population structure by sequencing the mitochondrial microsatellite (short tandem repeat, mtSTR) in 786 samples from 11 nesting sites spanning 700 km from Canaveral National Seashore through Dry Tortugas National Park. The mtSTR marker subdivided CM-A3.1 into 12 haplotypes that were structured among rookeries, demonstrating independent female recruitment into the Dry Tortugas and Marquesas Keys nesting populations. Combined haplotypes provided support for recognition of at least 4 management units in Florida: (1) central eastern Florida, (2) southeastern Florida, (3) Key West National Wildlife Refuge, and (4) Dry Tortugas National Park. Recapture data indicated female nesting dispersal between islands &lt;15 km apart, but haplotype frequencies demonstrated discrete natal homing to island groups separated by 70 km. These isolated insular rookeries may be more vulnerable to climate change-mediated nesting habitat instability than those along continental coasts and should be monitored more consistently to characterize population status. Broader application of the mtSTR markers holds great promise in improving resolution of stock structure and migratory connectivity for green turtles globally.

Biophysical model of coral population connectivity in the Arabian/Persian Gulf.

The coral reef ecosystems of the Arabian/Persian Gulf (the Gulf) are facing profound pressure from climate change (extreme temperatures) and anthropogenic (land-use and population-related) stressors. Increasing degradation at local and regional scales has already resulted in widespread coral cover reduction. Connectivity, the transport and exchange of larvae among geographically separated populations, plays an essential role in recovery and maintenance of biodiversity and resilience of coral reef populations. Here, an oceanographic model in 3-D high-resolution was used to simulate particle dispersion of "virtual larvae." We investigated the potential physical connectivity of coral reefs among different regions in the Gulf. Simulations reveal that basin-scale circulation is responsible for broader spatial dispersion of the larvae in the central region of the Gulf, and tidally-driven currents characterized the more localized connectivity pattern in regions along the shores in the Gulf's southern part. Results suggest predominant self-recruitment of reefs with highest source and sink ratios along the Bahrain and western Qatar coasts, followed by the south eastern Qatar and continental Abu Dhabi coast. The central sector of the Gulf is suggested as recruitment source in a stepping-stone dynamics. Recruitment intensity declined moving away from the Straits of Hormuz. Connectivity varied in models assuming passive versus active mode of larvae movement. This suggests that larval behaviour needs to be taken into consideration when establishing dispersion models, and establishing conservation strategies for these vulnerable ecosystems.

Distribution of the Mediterranean ribbed limpet Patella ferruginea Gmelin, 1791 along the Ligurian coast and implications for conservation actions

Patella ferruginea is an endemic limpet of the Western Mediterranean Sea, presently considered the most threatened marine macroinvertebrate in the region and included in several international conservation directives. Its populations were widespread throughout the Western Mediterranean in the late Pleistocene (Tyrrhenian period), still largely distributed until the 19th century and presently confined into small populations in few restricted areas due to human harvesting for food and baits, construction of coastal infrastructures and the effects of seawater pollution. In particular, the species was reported as presently missing in the whole of the Italian continental coasts and measures are in progress to reintroduce the species through translocation and reproduction in controlled conditions along the Ligurian coasts (North-western Mediterranean).Recent surveys along the Ligurian coasts, performed to assess the most suitable sites for reintroduction, allowed the discovery of 32 specimens of this endemic limpet, considered disappeared in the area. These findings shed new light on the ability of natural dispersion of the species, the relevance of the measures set in place to restore the presently rarefied populations and provide hints for the selection and management of sites within the Natura 2000 Ecological network.

Morphological Variability of Phorcus lineatus (da Costa, 1778) Shells along the Coast of Portugal and the Significance of the Environment on Shell Morphology

Phorcus lineatus (da Costa, 1778) is a marine intertidal gastropod occurring in the Eastern Atlantic, from Northern Ireland and Wales to Mauritania. Along the Portuguese continental coast, it displays marked shell variability. Northern shells have a worn spire, but southern specimens display good preservation. At most sites, the majority of shells show no umbilicus, but at sites scattered along the coast, most shells display a distinct or conspicuous umbilicus. In order to understand these discrepancies, I carried out analyses of the mean grain size of the beach sand where live animals were collected and estimations of the annual mean wave height near the sampling sites by using Portuguese Institute for Sea and Atmosphere (IPMA) forecasts. Sampling, experiments and data loading were carried out in the period 2012–2015. Whereas no direct correlation was found between umbilicus prominence, shell size and studied environmental variables, abrasion and wear of the spire were found to be primarily dependent upon sea wave height and on beach sand grain size. It was concluded that current malacological literature, particularly field guides, sub-represent the morphological diversity of P. lineatus shells omitting eroded shells, and that worn shells occur along the distribution range of this species. Abrasion and wear of P. lineatus shells appear to increase with increasing sea wave height, and also with increasing beach sand grain size, reflecting the intensity of the hydrodynamics at a local scale.

Millennial‐scale change in the structure of a Caribbean reef ecosystem and the role of human and natural disturbance

Caribbean coral reefs have transformed into algal‐dominated habitats over the past half‐century, but the role of specific anthropogenic drivers is unresolved due to the lack of ecosystem‐level data predating human disturbance. To better understand the extent and causes of long‐term Caribbean reef declines, we produced a continuous 3000‐yr record of the ecosystem state of three reefs in Bocas del Toro, Caribbean Panama. From fossils and sediments obtained from reef matrix cores, we tracked changes in reef accretion rates and the taxonomic and functional group composition of fish, coral, urchin, bivalve and benthic foraminifera. This dataset provided a comprehensive picture of reef community and environmental change. At all sites, reefs shifted from systems with greater relative abundance of herbivorous fish, epifaunal suspension feeding bivalves and Diadema urchins to systems with greater relative abundance of micropredator fish, infaunal bivalves and Echinometra urchins. These transitions were initiated a millennium ago at two less‐degraded reefs fringing offshore islands and ~250 yr ago at a degraded patch reef near the continental coast. Ecosystem shifts were accompanied by a decline in reef accretion rates, and at the patch reef, a decline in water quality since the 18th century. Within all cores, synchronous increases in infaunal bivalves and declines in herbivorous fish regardless of water quality suggest a loss of hard substrate and increasingly hypoxic sediment conditions related to herbivore loss. While the early timing of ecosystem transitions at the fringing reefs implicates large‐scale hydrological change, the more recent timing of change and loss of water quality at the patch reef implicates terrigenous runoff from land‐clearing. Our whole‐ecosystem reconstruction reveals that reef ecosystem deterioration appears to follow a predictable trajectory whether driven by natural or anthropogenic disturbances and that historical local human activities have quickly unraveled reefs at a scale similar to longer‐term natural environmental change.

Connections Between Benthic Populations and Local Strandings of the Southern Bull Kelp Durvillaea Antarctica Along the Continental Coast of Chile1.

Floating seaweeds are important dispersal vectors in marine ecosystems. However, the relationship between benthic populations and stranded seaweeds has received little attention. After detachment, a fraction of floating specimens returns to the shore, resulting in strandings that fluctuate in space and time. It has been hypothesized that the availability of stranded seaweeds is related to their benthic abundance on adjacent coasts. Using the large fucoid Durvillaea antarctica, we tested whether stranded biomasses are higher at sites with dense adjacent benthic populations. Benthic abundance of D.antarctica along the continental coast of Chile was estimated using three approximations: (i) availability of potentially suitable habitat (PSH), (ii) categorical visual abundance estimates in the field, and (iii) abundance measurements in the intertidal zone. Higher PSH for D.antarctica was observed between 31°S-32°S and 40°S-42°S than between 33°S and 39°S. Lowest benthic biomasses were estimated for the northern latitudes (31°S-32°S). Regression models showed that the association between stranded biomass and PSH was highest when only the extent of rocky shore 10km to the south of each beach was included, suggesting relatively short-distance dispersal and asymmetrical transport of floating kelps, which is further supported by low proportions of rafts with Lepas spp. (indicator of rafting). The results indicate that stranded biomasses are mostly subsidized by nearby benthic populations, which can partly explain the low genetic connectivity among populations in the study region. Future studies should also incorporate other local factors (e.g., winds, currents, wave-exposure) that influence stranding dynamics.

New records and update on the geographic distribution of the Bonyeared&amp;nbsp;Assfish, Acanthonus armatus G&amp;uuml;nther, 1878 (Ophidiidae,&amp;nbsp;Neobythitinae), in the Caribbean region

Acanthonus armatus Günther, 1878 is reported for the first time in the southwestern Caribbean region, off Colombia. Remote Operate Vehicle videos and towed camera still photographs captured 13 images of A. armatus between 2215 and 2564 m. These are the first records of the species in the Caribbean continental coast of Colombia, representing a range extension to the southwestern Caribbean region, since previous records are from the northeastern Caribbean. Some photos of the specimens and the current distribution of the species in the Caribbean region are provided and reviewed.

Striped dolphins as trace element biomonitoring tools in oceanic waters: Accounting for health-related variables

In Europe, monitoring contaminant concentrations and their effects in the marine environment is required under the Marine Strategy Framework Directive (MSFD, 2008/56/EC). The striped dolphin (Stenella coeruleoalba) is the most abundant small cetacean species in Portuguese oceanic waters, representing a potential biomonitoring tool of contaminant levels in offshore waters. Concentrations of nine trace elements were evaluated by ICP-MS in kidney, liver and muscle samples of 31 striped dolphins stranded in the Portuguese continental coast. The mean renal Cd concentration was high (19.3 μg.g−1 wet weight, range 0.1–69.3 μg.g−1 wet weight) comparing to striped dolphins from other locations. Therefore, the present study reports a possibly concerning level of Cd in the oceanic food chain in Portuguese offshore areas. This study also aimed at evaluating potential relationships between trace element concentrations and striped dolphins' biological and health-related variables. Individual length was related with some of the trace element concentrations detected in striped dolphins. Indeed, Cd, Hg and Se bioaccumulated in larger animals, whereas the reverse was observed for Mn and Zn. Striped dolphins with high parasite burdens showed higher levels of Hg, while animals showing gross pathologies presented higher concentrations of Cd and Se. This study reported relationships between trace element concentrations and health-related variables for the first time in striped dolphins and it also provided information on the relative contamination status of Portuguese oceanic waters in comparison to other regions in the world.

Cryptic diversity in smooth-shelled mussels on Southern Ocean islands: connectivity, hybridisation and a marine invasion

BackgroundLarge numbers of endemic species inhabit subantarctic continental coasts and islands that are characterised by highly variable environmental conditions. Southern hemisphere populations of taxa that are morphologically similar to northern counterparts have traditionally been considered to be extensions of such Northern hemisphere taxa, and may not exhibit differentiation amongst geographically isolated populations in the Southern Ocean. Smooth-shelled blue mussels of the genus Mytilus that exhibit an anti-tropical distribution are a model group to study phylogeography, speciation and hybridisation in the sea, and contribute to the theory and practice of marine biosecurity.MethodsWe used a single nucleotide polymorphism (SNPs) panel that has the ability to accurately identify reference Northern and Southern hemisphere Mytilus taxa to test for evolutionary differentiation amongst native Southern Ocean island populations.ResultsNative mussels from the Falkland Islands and the Kerguelen Islands exhibited greatest affinity to native M. platensis d’Orbigny 1846 from the Atlantic coast of South America. The major Southern Ocean current flow from west to east is likely to explain the spreading of M. platensis to remote offshore islands, as adults via the process of rafting or perhaps directly as larvae. SNPs variation revealed that mussels from Tasmania were native and clearly differentiated from all other blue mussel groups in the Southern and Northern hemispheres. The native mussels M. planulatus from Tasmania and from mainland New Zealand (NZ), and tentatively M. aoteanus from the two NZ Southern Ocean offshore island groups (the Auckland Islands and Campbell Island), formed a distinct M. galloprovincialis–like Southern hemisphere group with closest affinity to Northern hemisphere M. galloprovincialis from the Mediterranean Sea. In all cases, the SNPs revealed evidence of hybridisation between two or more distinct taxa. The invasive Northern hemisphere M. galloprovincialis was identified only in Tasmania, amongst native mussels of a distinct Australian M. planulatus lineage.ConclusionOverall, our results reveal that Southern hemisphere island mussels have mixed genome ancestry and are native, not introduced by human activities. The preservation of distinct evolutionary lineages of Southern hemisphere species needs to be an ongoing focus of conservation efforts, given that population sizes on some of the remote offshore oceanic islands will be small and may be more easily adversely affected by invasion and subsequent hybridisation and introgression than larger populations elsewhere.

An evaluation of human interventions in the anthropogenically disturbed Caribbean Coast of Colombia

Although human interventions have influenced many coastal areas around the world, research has rarely assessed the environmental impacts of these anthropogenic perturbations. To understand the dominant coastal interventions in countries with tropical areas, this study established a baseline along the continental Caribbean coast of Colombia (approximates 1700 km), based on 29 types of human interventions cataloged via Google Earth images. In total, of the 2742 human interventions identified, the most common were low-density-settlements (n = 971), groins (n = 738), and luxury settlements with piers (n = 188). In addition, the study assessed the environmental impact of each type of intervention based on the extent, intensity, reversibility, and persistence of their effect on coastal processes, as well as their frequency of appearance in the study area. The three most impactful types of human intervention were equivalent to those with the highest frequency: a. Low-density settlements; b. Groins/Jetties; c. Luxury settlements with a pier. In addition, the highest values of environmental impact correspond to material extractions and infrastructure assets such as breakwaters and seawalls. None of these anthropogenic disturbances, however, were within the ten most impactful interventions identified in the study area. The socio-natural patterns of coastal development identified by this study can steer integrated environmental management in coastal tropical countries with rapid economic growth, diversity of human interventions and heterogeneous geographical distribution.