Corals of the genus Porites are a locally abundant component of the epibiont community on mangrove prop roots at Calabash Caye, Turneffe Atoll, Belize

Mangroves are generally regarded as inhospitable for corals, but recent reports suggest they provide ecological refuge for some species. We surveyed diverse mangrove habitats on Turneffe Atoll, Belize, documenting 127 colonies of Porites divaricata (Thin Finger Coral) along 1858 m of mangrove prop roots at Calabash Caye and a much more diverse coral assemblage at Crooked Creek. At Calabash, corals were highly clumped, and varied widely in size and morphology, including large well-arborized colonies, encrusting forms with few branches, and new recruits with no branches, suggesting an age-structuredpopulation exhibiting extensive morphological plasticity. The data described here contributeto an emerging picture of mangroves as potentially critical habitat for many Caribbeancoral species.Accepted manuscrip

Distinct phenotypes associated with mangrove and lagoon habitats in two widespread caribbean corals, porites astreoides and porites divaricata.

AbstractAs coral reefs experience dramatic declines in coral cover throughout the tropics, there is an urgent need to understand the role that non-reef habitats, such as mangroves, play in the ecological niche of corals. Mangrove habitats present a challenge to reef-dwelling corals because they can differ dramatically from adjacent reef habitats with respect to key environmental parameters, such as light. Because variation in light within reef habitats is known to drive intraspecific differences in coral phenotype, we hypothesized that coral species that can exploit both reef and mangrove habitats will exhibit predictable differences in phenotypes between habitats. To investigate how intraspecific variation, driven by either local adaptation or phenotypic plasticity, might enable particular coral species to exploit these two qualitatively different habitat types, we compared the phenotypes of two widespread Caribbean corals, Porites divaricata and Porites astreoides, in mangrove versus lagoon habitats on Turneffe Atoll, Belize. We document significant differences in colony size, color, structural complexity, and corallite morphology between habitats. In every instance, the phenotypic differences between mangrove prop root and lagoon corals exhibited consistent trends in both P. divaricata and P. astreoides. We believe this study is the first to document intraspecific phenotypic diversity in corals occupying mangrove prop root versus lagoonal patch reef habitats. A difference in the capacity to adopt an alternative phenotype that is well suited to the mangrove habitat may explain why some reef coral species can exploit mangroves, while others cannot.Published versio

The importance of mangroves as coral habitat in a deteriorating ocean – an ecological, demographic, and genomic research program on model mangrove corals in the genus Porites

Coral reefs and many of the coral species that construct them are in a state of global decline, and this rapid decline of reef corals has incited worldwide conservation, restoration, and research efforts. One growing area of research involves exploring the value of reef-associated habitats, like mangroves, for the survival of particular coral species and the resilience of nearby reefs. Mangroves have long been regarded as inhospitable habitat for corals due to their combination of low light levels, low water clarity, and fluctuating water temperatures. However, roughly half of the coral species living on Caribbean reefs have been documented to inhabit mangrove habitats. If mangroves constitute a critical component of the ecological niche for some corals, then they should support viable, self-sustaining populations. If mangroves contribute directly to the resilience of reef coral populations, then corals must be able to exploit both habitat types coping with varying environmental conditions. Despite the growing number of documented mangrove-coral communities, these questions have not been studied. Here I use two Caribbean coral species from the genus Porites that are known to inhabit both reef and mangrove habitats (P. astreoides and P. divaricata) to explore the contribution of mangrove habitats to coral survival via the following objectives: 1) Characterize the survival, growth, and spatial-distribution of a mangrove-dwelling population of P. divaricata through a multi-year field study; 2) Determine if the population characterized in objective 1 is capable of self-recruitment and map dispersal through a population genomic study using 2bRAD markers; 3) Determine how key phenotypic traits vary between reef and mangrove habitats in P. divaricata and P. astreiodes, using a cross-habitat comparative field-study. Results suggest that mangroves may serve as important habitat for some reef corals due to their ability to support a viable, stable, and healthy coral population that is self-sustaining largely through asexual reproduction. Subsequently, mangrove and reef corals display predictable differences in phenotype, that could help reveal how a “reef coral” can exploit darker mangroves. This work can inform the design of marine protected areas, whereby both mangroves as well as the connection between mangroves and reefs is preserved to facilitate coral survival.2024-03-02T00:00:00

Using bioindicator species to characterize distinct mangrove habitats on Turneffe Atoll, Belize

Mangroves are critical to the biodiversity and productivity of tropical ecosystems, and for this reason, they are part of the foundation for Belize’s Blue Economy. Despite their ecological and economic significance, mangroves are among the most threatened marine habitats in the world. Turneffe Atoll, home to the largest and newest marine reserve in Belize, is unique among the four atolls located along the Mesoamerican barrier reef in that it is dominated by mangroves. In an effort to investigate the role of Turneffe’s mangroves in supporting marine biodiversity, we conducted longitudinal surveys of the epibionts (marine species inhabiting the submerged mangrove roots). From 2016-2017, in two low-flow ponds and two high-flow channels, we scored the presence or absence of 28 indicator species on 182 roots (a total of 5096 observations). We observed significant differences between sites in the proportion of roots occupied by several indicator species, and we documented substantial stability from year-to-year in the presence of specific indicators. We also conducted exhaustive surveys of mangrove corals, revealing that particular mangroves on Turneffe appear to be important habitat for corals. Over a 4-year period, one population of the thin finger coral (Porites divaricata) occupying a few hundred meters of shoreline at Calabash Caye exhibited gradual population growth over multiple years. While all mangrove-lined shores may appear similar to observers on passing boats, beneath the water, mangrove communities are diverse, and this diversity is critical to their wider role in the health of coastal ecosystems. The study described here revealed that mangrove epibiont diversity on Turneffe Atoll varies over fine spatial scale in a manner that may be predictable, e.g., some mangrove species are generalists, while others are specialists found in selective mangrove habitats. Of course, “natural” patterns of species distribution are a reflection of habitat quality, which is directly impacted by human activities. Continuing longitudinal studies of biodiversity in these understudied habitats will be essential to monitoring the health of Turneffe Atoll and the health of Belize’s coastal ecosystems generally.Published versio

Supporting Information from Shifts in predator behaviour following climate induced disturbance on coral reefs

This file contains supplementary table 1 and supplementary figure