Seaflower Biosphere Reserve Research Articles

Fish biodiversity of Courtown Cays, seaflower biosphere reserve (Colombian Caribbean): new records and an annotated checklist

Fish biodiversity of Courtown Cays, seaflower biosphere reserve (Colombian Caribbean): new records and an annotated checklist

FIRST REPORT ON THE DISTRIBUTION AND EXTENSION OF SEAGRASS MEADOWS IN QUITASUEÑO CORAL BANK, SOUTHWESTERN CARIBBEAN

Seagrass beds constitute one of the world’s most productive marine ecosystems and are a source of food and shelter for a wide variety of species. The largest extension of seagrass meadows in the Seaflower Biosphere Reserve (Seaflower BR) is found around the Caribbean islands of San Andres, Old Providence, and Santa Catalina, with small patches around the cays Bolivar, Albuquerque, and Serranilla. Previous studies have reported the presence of seagrass beds in the Quitasueño Bank; however, they remain undescribed, without previous information about their extent and distribution within the coral complex. In November 2021, during the Seaflower Plus 2021 scientific expedition, extensive seagrass meadows were detected, and their distribution was determined through the interpretation of satellite images and analyses of information obtained in the field through rapid ecological assessments. It was determined that these meadows cover 619.7 ha, positioning Quitasueño as the second largest area in terms of seagrass coverage in the Seaflower BR after Old Providence and Santa Catalina islands. This new information increases the representativeness of the seagrass ecosystem within the National System of Protected Areas of Colombia and should be considered in future research and management efforts.

Extreme high stress temperatures in Fall 2023 generate mass coral reef bleaching in the western Caribbean, Seaflower Biosphere Reserve

Extreme high temperatures exceeding bleaching thresholds (DHW) occurred at San Andres Island, Seaflower Bosphere Reserve causing massive bleaching on coral reefs and reefs crests—key ecosystems for coastal protection, wellbeing, and economy of the island. We present aerial images comparing the same reef crest during 2022 (no bleaching) and 2023 (bleaching).

Notes on the marine algae of the International Biosphere Reserve Seaflower, Caribbean Colombia IX: new records of Lobophora declerckii, Taonia abbottiana and Verosphacela ebrachia for Colombia

Background and Aims: During the Seaflower Scientific Expedition in 2019, extensive seaweed collection was carried out around Old Providence and Santa Catalina islands. Despite the intensive phycological studies realized during the past decade, new reports of macroalgae are still recorded for the Seaflower Biosphere Reserve. The objective of this work is to present three new records of brown algae for Colombia.Methods: The algal sampling was carried out in September 2019 during the Seaflower Scientific Expedition. The samples were collected around the Providencia and Santa Catalina islands in coral patches ecosystems, by SCUBA diving at depths between 3 and 16 m. The algae collected were preserved in a 4% formalin/seawater solution. The identification was carried out using optical and stereoscopic microscopes. All specimens were deposited in the herbarium JIW of the Biology Department of the Universidad Nacional de Colombia, Bogotá, Colombia. Key results: Three species of brown algae are newly reported for Colombia: Lobophora declerckii, Taonia abbottiana and Verosphacela ebrachia. Verosphacela has been reported, to date, only from the type locality in Florida and from Isla Mujeres, in Mexico. Due to its cryptic and small habit, it may be much more common than actually reported. Lobophora declerckii is apparently the most common species of Lobophora in the Archipelago. Taonia abbottiana may be much more common than reported to date, but it is easily confused with Stypopodium zonale. Conclusions: Despite the intense phycological research carried out in the past decade in the Archipelago of San Andrés, Old Providence and Santa Catalina, there is still much to be discovered.

Miocene Fossils of Old Providence Island (Western Caribbean, Colombia) and Geological Heritage of the Seaflower Biosphere Reserve

Miocene Fossils of Old Providence Island (Western Caribbean, Colombia) and Geological Heritage of the Seaflower Biosphere Reserve

METAL CONCENTRATIONS IN <i>Isognomon alatus</i> BY STAGES AND CLIMATIC SEASONS IN SAN ANDRÉS ISLAND, COLOMBIAN CARIBBEAN

This study evaluates the potential of the flat oyster Isognomon alatus as a biomonitor species for metal contamination, based on bioaccumulation patterns in adults and juveniles present in the Seaflower Biosphere Reserve on San Andrés Island (Colombia) in three seasons climatic. The analysis by Atomic Absorption Spectrometry of I. alatus specimens and water samples collected in SAI (2009 and 2010) allowed us to observe higher concentrations (Max: 2,235 μg/g dry weight) of Zn in seston, compared to Cd (Max: 0.078 μg/g dry weight) and Cu (Max: 0.069 μg/g dry weight). These concentrations varied seasonally in relation to the intensity of rainfall in the area. By means of a two-way ANOVA (p<0.05), statistically significant differences were determined between sampling sites and seasons for metal concentrations (Cd, Cu, Zn) in organisms and for the Bioconcentration Factor (BCF), which corresponds to the relationship between the metal concentration in oysters and seston. Regarding the effect of age/size, the Cd concentration obtained and evaluated by ranges in juveniles is significantly lower than that observed in adults during the dry season, like what was recorded in other oyster studies. A comparison of the results obtained with the available data for I. alatus indicated that SAI had been impacted by Zn contamination. The results confirm the bioavailability of Cd previously reported; and the bioaccumulation of metals, especially Cu and Zn, according to FBC estimates.

Coral reef degradation at an atoll of the Western Colombian Caribbean.

Coral reef decline is an issue of concern around the globe. Remote and uninhabited coral areas are not exempt from facing changes in species composition and functionality due to global drivers. Quitasueño is a remote atoll within the Seaflower Biosphere Reserve, in the Southwestern Caribbean Sea. To evaluate the current status of the coral reefs in Quitasueño we sampled 120 stations through Rapid Ecological Assessment and evaluated four stations through Planar Point Intercept to compare the current percent cover of benthic groups with previous studies in the area. We found pronounced changes in coral and macroalgae covers in time, and great conspicuousness of multiple conditions of deterioration along Quitasueño, including diseases, coral predation, and aggression and invasion of coral colonies by macroalgae and sponges. The reef ecosystem seems to be facing a phase shift, in which the benthic cover previously dominated by hard corals is currently dominated by fleshy macroalgae. It is essential to evaluate the possible drivers of the extent of degradation of Quitasueño to understand the process of deterioration and mitigate the impacts.

Trash in paradise: marine debris on the beaches of San Andrés Island, Seaflower Biosphere Reserve, Colombian Caribbean

San Andres Island is one of the main touristic places in Colombia, and its main attractions are its sandy beaches and the marine coastal ecosystems, such as coral reef and seagrass beds. However improper behavior of both residents and tourists on solid residue disposal may threaten not only the aesthetic of the island ́s beaches, but also poses risk to marine life. The objective of this research was to assess the amount of litter on the main beaches of the island. We surveyed three popular beaches for ten weeks. We collected 9894 units of litter, equivalent to a weight of 23 212.47 g. Beach cleanliness was estimated using the Clean Coast Index, and two of the three sites resulted “extremely dirty”, while the third was classified as “dirty”. The majority of the litter was plastic (59.5 % of total weight), followed by glass (20.4 %). Due to the persistence and negative effects of solid waste on coastal fauna, it is necessary to improve the management of litter disposal, and improve educational programs for both residents and tourists, to increase their awareness on the problem.

Rising sea level and increasing tropical cyclone frequency are threatening the population of San Andrés Island, Colombia, western Caribbean

The Colombian island of San Andrés is a popular tourist destination located about 195 km offshore of the east coast of Nicaragua in the southwestern Caribbean Sea. Together with Providencia and Santa Catalina, San Andrés is part of the UNESCO Seaflower Biosphere Reserve. With a 26 km2 surface area and 78 000 inhabitants, San Andrés is one of the most densely populated islands in the Caribbean with on average ∼ 3000 inhabitants/km2. The majority of the population and the mass tourism are concentrated in the low-elevation (0.5–6 m) areas, particularly in the north and along the east coast of the island. These areas are prone to flooding during storm events such as hurricanes Eta and Iota in 2020. A review of the geological, environmental and the socio-economic situation of the island, and the record of tropical cyclones since 1911, shows why the local population has become increasingly vulnerable to storm events and rising sea level. Tropical cyclones may form locally in the southwestern Caribbean or originate in the eastern Caribbean/Atlantic Ocean. The latter tend to be stronger and cause more damage when they reach San Andrés. The HURDAT2 dataset shows that the frequency of storm events affecting San Andrés has increased in recent decades, with six storms over the past 20 years, including three category 4-5 hurricanes since 2007. Increasing storm frequency and intensity may be linked to increasing sea surface temperatures caused by anthropogenic global warming, although the changes described here may be limited to a relatively small geographical region, as opposed to representing basin wide tropical cyclone behavior. The growing population density since the 1950s has augmented the potential for disaster.

Where does marine litter hide? The Providencia and Santa Catalina Island problem, SEAFLOWER Reserve (Colombia)

The SEAFLOWER Biosphere Reserve (SBR) is the largest Marine Protected Area in the Caribbean Sea and the second largest in Latin America. Marine protected areas are under pressure from various stressors, one of the most important issues being pollution by marine litter, especially plastic. In this study our aim is to establish the distribution pattern and potential sources of solid waste in the different marine/coastal ecosystems of the islands of Providencia and Santa Catalina (SBR), as well as assess any interconnections between these ecosystems. At the same time, the distribution characteristics of marine litter in the different compartments facilitated a more dynamic understanding of the load of marine litter supplied by the islands, both locally and externally. We observed that certain ecosystems, principally back-beach vegetation and mangroves, act as crucial marine litter accumulation zones. Mangroves are important hotspots for plastic accumulation, with densities above eight items/m2 (minimum 8.38 and maximum 10.38 items/m2), while back-beach vegetation (minimum 1.43 and maximum 7.03 items/m2) also removes and stores a portion of the marine litter that arrives on the beaches. Tourist beaches for recreational activities have a low density of marine litter (minimum 0.01 and maximum 0.72 items/m2) due to regular clean-ups, whereas around non-tourist beaches, there is a greater variety of sources and accumulation (minimum 0.31 and maximum 5.41 items/m2). The low density of marine litter found on corals around the island (0–0.02 items/m2) indicates that there is still no significant marine litter stream to the coral reefs. Identifying contamination levels in terms of marine litter and possible flows between ecosystems is critical for adopting management and reduction strategies for such residues.

Editorial: SeaFlower Biosphere Reserve: New Findings and Trends in the Largest Caribbean Marine Protected Area

Editorial: SeaFlower Biosphere Reserve: New Findings and Trends in the Largest Caribbean Marine Protected Area

Geomorphological units and distribution of sedimentary facies in the Alburquerque Key Island, Seaflower Biosphere Reserve, Colombian Caribbean

Se caracterizaron las unidades geomorfológicas mediante técnicas de sensoramiento remoto (imágenes satelitales y acústico) y se determinó la distribución de las facies sedimentarias validadas con datos in situ en la Isla Cayos de Alburquerque como una contribución al conocimiento de la Reserva de Biosfera de Seaflower. Esta isla cayos presenta una geomorfología típica de un atolón con Bajos arrecifales, Cuenca lagunar, Terraza lagunar, Terraza prearrecifal, Talud y Arrecife periférico, el cual presenta una extensión aproximada de 6 km que son impactados por el fuerte oleaje originados por los vientos alisios del noreste. Se lograron establecer 10 facies sedimentarias de composición biolitoclástica y bioclástica de formaciones coralinas y del basamento volcánico del atolón, con una distribución heterogénea. Este estudio permite establecer una línea base para el conocimiento de la dinámica del transporte y depósito de los sedimentos en las plataformas arrecifales.

Reef Structural Complexity Influences Fish Community Metrics on a Remote Oceanic Island: Serranilla Island, Seaflower Biosphere Reserve, Colombia

Serranilla is a protected island of the Seaflower Biosphere Reserve, far from dense human population. These characteristics could help sustain structurally complex coral reefs, often associated with higher biodiversity, abundance, and biomass of reef-associated organisms, including reef fish. However, the multiple threats present in Serranilla, including intense illegal fishing, can impact coral ecosystems generally and also specific key groups, such as the parrotfish, in particular. During the “Seaflower Research Expedition 2017”, we assessed how structural habitat complexity influences reef fish assemblages. In addition, we explored differences in parrotfish species (family: Scaridae) between Serranilla and San Andrés, the most populated island in the Archipelago. On Serranilla, we found that habitat structure, rugosity, and coral cover accounted for up to 66% of variation in reef fish diversity, abundance, and biomass, with values being higher on more complex reefs. Parrotfish species differed between the islands, with larger species supporting higher biomasses at Serranilla, by comparison with San Andrés; however, the abundance, biomass, and lengths of parrotfish species were low in both areas compared with those reported from other protected Caribbean reefs. Our study indicates that despite the evident relationship between structurally complex habitats and reef fish, other threats in Serranilla could be affecting parrotfish populations, such as illegal fishing, a widespread activity in the area.

Ecological shallow water delimitation of the Serrana, Roncador, and Quitasueño Atolls of the Seaflower Biosphere Reserve in the Colombian Caribbean

I n order to contribute to the sea bottoms knowledge of the Seaflower Biosphere Reserve (RB Seaflower), a mapping update was made at 1:50,000 scale of the Seascape Ecological Units (SEU) for the Serrana, Roncador and Quitasueño atolls, based on the processing and interpretation of ALOS AVNIR – 2 satellite images acquired in 2012. For the attribute assignation was used as reference cartographic products, fieldwork data, and ecological descriptions of the benthic community. A total of 138,967 ha and 30 SEU, which corresponds to 32,908 ha for Serrana, 4,861 to Roncador and 101,198 to Quitasueño. The products generated represents a good approximation of the location, extension and distribution of the benthic seascape elements, constituting the base line information for the management of these atolls, they are also part of the Continental, Coastal and Marine Ecosystem Map of Colombia at scale 1:100,000 (MEC 100K) and the Colombian Coral Areas Atlas (AACC) updated on a digital platform to 2020. However, more extensive field work is needed for cartographic purposes, which allows for greater spatial and thematic detail, and to evaluate cartographic reliability

Biodiversity and Ecological Units of the Mesophotic Coral Ecosystems in San Andrés Island, SeaFlower Biosphere Reserve

Biodiversity and Ecological Units of the Mesophotic Coral Ecosystems in San Andrés Island, SeaFlower Biosphere Reserve

Marine litter arrived: Distribution and potential sources on an unpopulated atoll in the Seaflower Biosphere Reserve, Caribbean Sea

The Albuquerque atoll was studied as a representative natural laboratory to explore the role of sea-based sources of marine litter. This work aimed to identify the small-scale spatial distribution of marine litter (i.e., plastic, glass, paper, and others) as well as to explore the connectivity among the atoll habitats (sand beach, water surface, and reef) to give insights of potential sources of marine litter (>5 cm), mainly plastics. Marine litter was dominated by plastic items, as expected, with an average value of 0.5 items/m2. Large microplastics (1–5 mm) were also sampled on beaches with an average value of 90 particles/m2. In the atoll inner lagoon, marine litter was also composed by plastic, mainly fragments (average 0.059 items/m3). The predominance of plastic fragments on both the sea surface and beaches of the atoll makes inferences on sources limited. However, o fishing activities and sea-based sources might be relevant since local sources are very limited.

Sea Turtles at Serrana Island and Serranilla Island, Seaflower Biosphere Reserve, Colombian Caribbean

Sea Turtles at Serrana Island and Serranilla Island, Seaflower Biosphere Reserve, Colombian Caribbean

Methodological approach for hydroacoustic seabed characterization in Serrana Bank (Seaflower Biosphere Reserve)

Hydroacoustic methods provide rapid and extensive access to seabed characteristics, which is not possible using other underwater technologies. Currently, hydroacoustics are widely used to determine seabed topography and sediment type, but significant developments have not occurred for detecting and classifying structures above the seabed, such as coral reefs and marine meadows, which are very important ecosystems. In the present study, we propose a new methodological approach to characterize the seabed at Serrana Bank (14.27°–14.48° N and 80.10°–80.23° W), located in the Colombian Basin of the Caribbean Sea, by combining acoustic information (split-beam echosounder) and underwater imagery. In all, 49 acoustic transects were created using a BioSonics DT-X scientific echosounder (with a 38-kHz split-beam transducer and a FURUNO differential GPS) during the Seaflower Scientific Expedition III (Colombian Ocean Commission, Colciencias) from August 12–15, 2016. Using cluster analysis with the Spearman correlation distance, 14 different Typical Acoustic Reflectance Profiles (TARPs) were identified at a distance of 0.80. These TARPs result from the natural acoustic signals produced by the sediment types and ecological structures present on the seabed. When comparing these TARPs with the photographic records and previous ecological maps, various ecological structures above the seabed were acoustically identified, such as coral debris, octocorals, macroalgae meadows, and several associations among coral and different sizes of macroalgae. The potential of this approach to generate a low-cost, automated method for mapping seabed ecosystems and to enable feasible assessments in marine protected areas is discussed.

Effect of a precautionary management measure on the vulnerability and ecological risk of elasmobranchs captured as target fisheries

The impact of fisheries on elasmobranch populations has been widely documented; however, baseline information on shark and batoid management remains limited, particularly in tropical areas and in developing countries. The use of precautionary measures and data-poor methods have been recommended as valuable tools to guide the management and conservation of marine taxa when information is scarce and the effect of fisheries on populations is evident. A Productivity Susceptibility Analysis (PSA) and intrinsic rebound potential (r) estimates were used to evaluate the vulnerability and resilience of elasmobranchs before and after a precautionary measure (closure of the fishery) was implemented in the Archipelago of San Andrés, Providencia and Santa Catalina, Colombia (Seaflower Biosphere Reserve). We identified locally large information gaps, specifically on the demographic and life history parameters of the 15 elasmobranch species (13 sharks and 2 rays) evaluated for the Archipelago. Including fishing effects, nine large commercial shark species were identified as the most vulnerable and with the lowest intrinsic rebound potential, while the least vulnerable species was the whale shark (Rhincodon typus), which presented the third highest value of r2M. Once the fishery was closed, the vulnerability of large sharks decreased greatly. Our findings highlight the importance of: involving communities to achieve effective management processes; implementing precautionary measures for high impact and targeted fisheries; and using valuable data-poor tools for the study of populations as an alternative for evaluating and suggesting management measures. Finally, based in PSA and intrinsic rebound potential results, it is suggested to maintain the fishing ban in consensus with the fishermen, and to evaluate economic alternatives already being generated in the area such as recreational diving and ecological tourism, among others.

NUEVO REGISTRO DE LA ESPECIE Cladopyxis hemibrachiata DEL GRUPO DINOFLAGENADO PARA LA RESERVA DE LA BIOSFERA DE SEAFLOWER, CARIBE COLOMBIANO

Los dinoflagelados son considerados como un grupo muy diverso, encontrados en la mayoría de los ambientes acuáticos, sin embargo, a pesar de la importancia de este grupo, son pocos los trabajos que se han hecho para el área del mar Caribe, siendo los registros más cercanos los reportados para el Golfo de México y la cadena submarina Vitória-Trindade en Brasil. En la presente nota se reporta por primera vez para el mar caribe colombiano la presencia de la especie de dinoflagelado Cladopyxis hemibrachiata Balech, en muestras colectadas en septiembre de 2017 en la Isla Cayo Serranilla (Reserva de biosfera Seaflower), mediante arrastres horizontales con una red cónica de 20 µm de tamaño de poro y diámetro del aro de 70 cm. Así mismo, se hicieron mediciones in situ de variables físicas y químicas del agua, cuyos datos obtenidos son típicos de aguas mesotróficas