The present research documents new distributional records of two gobioid fishes, Acentrogobius vanderloosi Allen, 2015 and Pseudogobius fulvicaudus Huang, Shao, and Chen, 2014 from the southeastern coast of India. Indian coastal waters provide suitable habitats for many gobioid fishes due to its varied ecosystems. The confusion over the identity of a number of gobioid fishes in India suggests the need for more studies on these fishes to better understand their diversity, taxonomy, and geographical distribution. The present record of these species from the southeastern coast of India expands the known distribution of these species.

Mangroves are subject to rapid and large-scale habitat changes, which threaten their unique genetic diversity and provision of critically important ecosystem services. Habitat fragmentation reduces connectivity, which can impair dispersal and lead to genetic isolation. However, it is unclear whether fragmentation could impact mangrove genetic isolation, as mangrove propagules appear to be able to disperse long distances. Here, we conducted a meta-analysis of studies testing for a correlation between geographic distance and genetic distance in mangrove plants. From the 22 studies that met the inclusion criteria, we found a significant isolation-by-distance effect; geographic distance was significantly associated with Nei’s genetic distance and FST. Our results show that mangrove propagules may be limited in their capacity to disperse across long distances, which highlights the importance of maintaining close proximity between habitat patches and reducing habitat fragmentation.

The paper describes the first report of Kandelia candel (Rhizophoraceae), a rare mangrove from Bhavanapadu, a coastal village in Srikakulam district in Andhra Pradesh, India. This species is relatively less abundant along the east coast of India. During our study covering all the 41 mangrove patches in the state of Andhra Pradesh, 16 mangrove species were observed throughout the state and the Kandelia candel was seen only in Bhavanapadu (patch 2). The plant sighted was identified using taxonomic keys and confirmed using DNA barcoding. The identified specimen is deposited in the museum repository at ICAR-Central Marine Fisheries Research Institute (CMFRI), Kochi (accession no. MB.1.1.1.1) and its gene sequence is deposited in National Center for Biotechnological Information (NCBI) (accession no. MH243746). Patch 2 where K. candel was observed is separated away from the other clusters in the principal component one, with the patch showing an average dissimilarity of about 71.79% from the other patches. K. candel is a mangrove highly sensitive to changes in salinity. The presence of a lone member of a rare species in the state at the sampling location raises questions on its endurance in the region. The study underlines the relevance of monitoring the mangroves and advocate adequate conservation measures for proper protection, proliferation and management of this globally dwindling resource.

Coasts are undeniably regions of critical importance for a range of environmental, sociocultural, and economic reasons. Yet they are also areas of intense anthropogenic impact and are particularly susceptible to climate change-related concerns. As such, it is imperative that we have the means to monitor and manage them in a sustainable manner. Drone technology has emerged as providing a unique value proposition in coastal environments to support data-driven monitoring and management decisions. With their highly detailed data capture capability, drones are particularly well suited to map the spatial heterogeneity, structural complexity, and temporally dynamic nature of coasts. Further, they are readily accessible to coastal populations and can promote grassroots action by the very people whose lives and livelihoods the coasts support. Herein, we cover several of the leading innovations in using aerial drones to map coastal ecosystems. We then consider how general trends and technology projections including artificial intelligence, as well as cloud and edge computing offer opportunities for the future of drone mapping and monitoring in a coastal context. While the challenge of change is inevitable, embracing the opportunities it provides will allow us to better understand and live sustainably with and within our coastal ecosystems.

Estuaries in Brazil are highly threatened environments and habitat loss is the main influential factor for the increase in the number of strandings of Antillean manatee (Trichechus manatus) calves in the north-eastern region of the country. The aim of the present study was to analyse and quantify the spatiotemporal dynamics of mangroves in the state of Paraíba and the association with manatee calf stranding events. The study area encompassed 10 remaining mangroves along the coast of the state, four of which were located within protected areas. Information on the mangrove forests was obtained from satellite images from the last four decades. Data on stranded Antillean manatee calves were obtained from a databank with records from 1980 to 2019. The data were analysed using geoprocessing techniques and statistical analyses. The results demonstrated changes in the mangrove forest over time, with larger areas existing during the 1980s, reductions in the following periods but a slight increase in the last decade. The number of stranded Antillean manatee calves increased over the years, with stranding events concentrated mainly on the northern coast of the state. The smallest number of stranding events occurred in the 1980s, when the mangrove forests were larger. Our findings confirm that the integrity of mangroves is of extreme importance to the maintenance and sustainability of Antillean manatee populations.

This paper describes the results of the surveys carried out along Ras Muari (Cape Monze, Karachi, Sindh) by the Italian Archaeological Mission in Lower Sindh and Las Bela in 2013 and 2014. The surveyed area coincides with part of the mythical land of the Ichthyophagoi, mentioned by the classical chroniclers. Many archaeological sites, mainly scatters and spots of fragmented marine and mangrove shells, were discovered and AMS dated along the northern part of the cape facing the Hab River mouth. The surveys have shown that fisher and shell gatherer communities temporarily settled in different parts of the headland. They began to exploit the sea resources during the Neolithic. However, the most important discovery consists of a unique fishers’ settlement with rectangular stone-walled structures located on a limestone terrace near Sonari (SNR-1), the first ever found along the northern coast of the Arabian Sea. The AMS dates show that it was settled mainly during the first half of the third millennium cal bc when the Indus Civilisation flourished in the area. Considering the importance of the discovery, all the material culture remains from the Sonari sites have been described and analysed in detail and, whenever possible, framed into the different phases of environmental changes and human adaptation to the coastal environment that have been interpreted thanks to a good series of AMS dates from marine and mangrove shells.

The Vulnerable fishing cat Prionailurus viverrinus faces a perilous future in South-east Asia. It was last sighted in Cambodia in 2003. We deployed 16 camera traps at four sites in southern Cambodia during January–May 2015 to determine if the fishing cat was still present in the country. Eight photograph/video captures of fishing cats were recorded from the mangroves in Peam Krasop Wildlife Sanctuary and one from Ream National Park, but there were no records from Botum Sakor National Park or Prey Nup. A number of other globally threatened species were also photographed in Peam Krasop Wildlife Sanctuary: the Sunda pangolin Manis javanica, the hog deer Axis porcinus and the large-spotted civet Viverra megaspila. We learnt of the killing of an alleged fishing cat at the Sanctuary in July 2015 in retaliation for raiding fishing nets. Illegal hunting and capture of fishing cats for the wildlife trade were reported by local informants at all sites. We provide photographic and video evidence of the fishing cats and highlight the importance of Cambodia's mangroves for threatened species conservation.

This article links up the disastrous history of fossil fuels with the celebrated ecology of mangroves. Building on ethnographic and historical research in Puerto Rico and St. Croix, it outlines the often neglected but quite consequential place of crude oil in the Caribbean. Following the construction of what became the second largest refinery in the world, I describe how the imperial energy networks of the United States first came to the Caribbean. Troubling a popular origin story of the Caribbean, colonial and industry leaders voiced a robust critique of the plantation in order to justify the introduction of these enclave refineries. Imperial energy networks welcomed an unprecedented problem to the region: coastal oil spills. The scientific and legal response to these spills brought new attention to the vital relationality of mangroves. Rather perversely, the destruction of the mangroves in the Caribbean—in which crude oil played the leading role—opened mangroves up to new forms of knowledge and care. While many claim that fossil fuels helped cultivate a modern disregard for the natural world, I show how the negative ecologies of fossil fuels also instigated new scientific and political appreciations for the liveliness of the natural world. This story of oil in the Caribbean has implications for scholarly debates around the so-called Anthropocene. Against scholarship that looks at the coming disaster of crude oil as an epochal break in thought and politics, this paper instead describes the long history of acknowledging and managing the disastrous qualities of fossil fuels.

Core MAN015 from Pacific coastal Guatemala contains sediments accumulated in a mangrove setting over the past 6500 yr. Chemical, pollen, and phytolith data, which indicate conditions of estuarine deposition and terrigenous inputs from adjacent dry land, document Holocene climate variability that parallels the Maya lowlands and other New World tropical locations. Human population history in this region may be driven partly by climate variation: sedentary human populations spread rapidly through the estuarine zone of the lower coast during a dry and variable 4th millennium B.P. Population growth and cultural florescence during a long, relatively moist period (2800–1200 B.P.) ended around 1200 B.P., a drying event that coincided with the Classic Maya collapse.

Laguna de la Leche, north coastal Cuba, is a shallow (≤ 3 m), oligohaline (∼ 2.0–4.5‰) coastal lake surrounded by mangroves and cattail stands. A 227-cm core was studied using loss-on-ignition, pollen, calcareous microfossils, and plant macrofossils. From ∼6200 to ∼ 4800 cal yr BP, the area was an oligohaline lake. The period from ∼ 4800 to ∼ 4200 cal yr BP saw higher water levels and a freshened system; these changes are indicated by an increase in the regional pollen rain, as well as by the presence of charophyte oogonia and an increase in freshwater gastropods (Hydrobiidae). By ∼ 4000 cal yr BP, an open mesohaline lagoon had formed; an increase in salt-tolerant foraminifers suggests that water level increase was driven by relative sea level rise. The initiation of Laguna de la Leche correlates with a shift to wetter conditions as indicated in pollen records from the southeastern United States (e.g., Lake Tulane). This synchronicity suggests that sea level rise caused middle Holocene environmental change region-wide. Two other cores sampled from mangrove swamps in the vicinity of Laguna de la Leche indicate that a major expansion of mangroves was underway by ∼ 1700 cal yr BP.

Palynological, loss-on-ignition, and X-ray fluorescence data from a 5.25 m sediment core from a mangrove forest at the mouth of the Shark River Estuary in the southwestern Everglades National Park, Florida were used to reconstruct changes occurring in coastal wetlands since the mid-Holocene. This multi-proxy record contains the longest paleoecological history to date in the southwestern Everglades. The Shark River Estuary basin was formed ~ 5700 cal yr BP in response to increasing precipitation. Initial wetlands were frequently-burned short-hydroperiod prairies, which transitioned into long-hydroperiod prairies with sloughs in which peat deposits began to accumulate continuously about 5250 cal yr BP. Our data suggest that mangrove communities started to appear after ~ 3800 cal yr BP; declines in the abundance of charcoal suggested gradual replacement of fire-dominated wetlands by mangrove forest over the following 2650 yr. By ~ 1150 cal yr BP, a dense Rhizophora mangle dominated mangrove forest had formed at the mouth of the Shark River. The mangrove-dominated coastal ecosystem here was established at least 2000 yr later than has been previously estimated.

We recently started a systematic approach to determine the reservoir age in southeast Arabia and its dependence on mollusk species and their environment. This part of the study concentrates on local reservoir age and stable isotopes of the lagoonal species Terebralia palustris and Anadara uropigimelana at Khor Kalba, Oman Sea. Environmental and nutritive influences on mollusks are reflected in the radiocarbon and stable isotope signal. We found a local reservoir age of A. uropigimelana of about 940 yr and that of T. palustris as 800 yr. Sclerochronological analyses yielded information about seasonality of growth and death in A. uropigimelana. The modern shell of Periglypta reticulata shares food resources and habitat with Anadara sp., of which we did not find a modern specimen. It provided information on response to changes in temperature in the lagoonal system needed for suitability as reflecting climatic conditions. We were interested in carbon pathways of the mangrove in Kalba and a mangrove planted anew on a former mangrove sediment in Ajman. Being an obvious source of charcoal and food of T. palustris makes this information necessary. Further analyses will be performed to interpret changes in reservoir age in complex lagoonal systems as reaction to environmental variability.

Mangroves create unique ecological environments, furnishing a habitat opportunity for many species. The majority of published information on mangrove sponges comes from the Caribbean while few data are available from Indo-Pacific mangrove sponges. In general, species diversity of sponges in mangroves is lower than adjacent subtidal habitats in both the Caribbean and Indo-Pacific. The aim of this study is to report the first data about sponge species diversity of two mangrove forests from Bangka Island (North Sulawesi, Indonesia) and to describe a new sponge species associated with the mangroves. The survey found 19 species, belonging to 11 families and 15 genera; the samples were collected on mangrove trunks, on the roots or on the surrounding bottom. The majority of the species are typical of coral reef but two of them have been previously found only in lagoons or in mangrove habitats. These new data enlarge our knowledge about Indonesian sponges diversity and suggest the urgency to consider Indonesian mangroves as an important but underestimated element in coral reef ecological dynamics.

Heteropanope glabra Stimpson, 1858 belonging to family Pilumnidae is reported for the first time from the mangrove mudflats of India. The identification of the species is difficult because the species shares similar morphological characters with other closely related species like Benthopanope indica (De Man, 1887). Studies in the past have reported the presence of H. glabra from coastal areas of Burma to Japan. The present study reports the presence of H. glabra on the western coast of India, which lies outside the old distribution range of the species.

This study investigated the presumed nursery function of mangroves for the ichthyofauna in East African swamp forests, Mida Creek. The species and size composition of the fish fauna and their trophic interactions were studied for five stations. Samples were collected during 5–6 consecutive days close to spring tide in mid-July 2011. Fish were caught using different types of passive fishing gear, such as large and small fyke nets, gill nets and, additionally, beach seines. All individuals were identified to species level, measured and preserved for further analyses. Stomach content analysis was applied to provide information about their diet. Stable isotope analysis was used to detect whether the source of primary production for the higher trophic levels is mangrove-related or not. A total of 27 fish species was recorded in a catch of 938 teleost specimens. Our analyses showed that a majority of fish belonged to the zoobenthivorous/omnivorous trophic mode, since they were partially feeding on invertebrates and on various other food sources. Two species (Sphyraena barracuda and Synodus variegatus) exhibited a mixed diet, with a piscivorous preference. Results concerning the population structure suggested that the fish community of Mida mainly consists of transient species. Juveniles were numerically more abundant in the whole Creek than adults. These findings support the hypothesis of a nursery function of the mangrove forests, Mida Creek.

From previously published studies we have learned that very fast-germinating species have some characteristics in common with cryptoviviparous species: (1) little or no endosperm/perisperm; (2) embryos fully developed and chlorophyllous at seed maturity; and (3) very fast germination, independent of temperature. Thus, we propose that these very fast-germinating seeds are ‘cryptoviviparous-like′.

Although semi-isolated mangrove lagoons are common in the Caribbean, few studies have surveyed organisms of multiple trophic levels and taxa in these lagoons, which are characterized by a lack of adjacent seagrass and coral-reef habitats. In this study, visual surveys, minnow traps and plankton tows, which were deployed at abutting mangrove prop roots and on macro-algal beds 5 and 15 m away from the prop roots, were used to study assemblages of fish and their potential prey in a semi-isolated lagoon located on Utila, Honduras during the dry season. Assemblages of fish and macro-crustacea differed between the three distances from prop roots, while zooplankton abundances were highly variable and did not follow any distinct distribution patterns. Daytime visual surveys found that large lutjanid (snapper) juveniles, tetraodontid (pufferfish), and some species of brachyurans were more abundant near prop roots. Small lutjanid juveniles were also significantly more numerous near prop roots, but their potential prey, copepods, showed no such difference in abundance. However, 24-hour minnow trap catches found that mean fish abundance (although low) did not differ between near-mangrove transects and transects located in algal beds away from prop roots. Whereas it is well known that mangrove–seagrass habitats play a vital role for fish in open systems, low abundances of organisms in algal beds, particularly in the day time, in this study indicate that algal beds may not be as important to fish in a semi-isolated mangrove lagoon.

The present study examined the effect of a catastrophic cyclone (Aila) on ichthyofaunal assemblages in a tidal river of the Sundarban Delta. Sampling in six stations with a gill-net of 20-m length and 1-cm mesh size resulted in the collection of 63 species in a pre-Aila survey. Among them, 16 species were not available in the year after the cyclone. However, 12 new species were added to the assemblages in the post-Aila year during which 59 species were recorded. Analysis of Similarity (ANOSIM) confirmed significant changes in fish assemblages after the cyclone with a corresponding reduction of the species diversity and variation in the seasonal pattern of abundance. Hydrological parameters also differed with a significant surge in nutrient concentrations. Tolerance to low dissolved oxygen seemed to be a determinant factor as evident from the higher abundance of certain fishes viz. Harpadon nehereus, Liza parsia, Pampus argentius, Tenualosa ilisha and Toxotes chatareus during post-Aila year. Despite the recovery of the ichthyofaunal assemblages at the later stage of the study, a strong seasonal variation was persistent. The study therefore suggests that environmental variation in terms of increasing temperature and salinity elicit greater response in an estuarine community than temporary natural disturbances even as severe as cyclones.