Recreational Diver Behavior and Contacts with Benthic Organisms in the Abrolhos National Marine Park, Brazil

Modeling risks in marine protected areas: Mapping of habitats, biodiversity, and cultural ecosystem services in the southernmost atlantic coral reef

Marine Protected Area (MPA) is a fundamental strategy for the maintenance of ocean ecological processes worldwide and, consequently, their associated ecosystem services. Nevertheless, the quality of the services provided by MPAs, including cultural services such as recreational activities, depends on the effective management of marine habitats and biodiversity. Here, we performed an ecosystemic assessment in reef environments within a subtropical MPA, modeling the potential risks for their habitats and their recreational activities. The Queimada Grande Island (QGI), southeastern Brazil, was used as the model area since this island encompasses a unique and irreplaceable marine habitat, the Southernmost Atlantic coral reef. We firstly assessed and mapped the habitats, the biodiversity, and the recreational activities associated with QGI reefs. Next, we considered different scenarios of management for the modeling risks across the study area. We found that the coral reef and its adjacent habitats, such as the rhodolith bed, make the sheltered face of the island an important area for the provision of the cultural ecosystem services and overlapping uses such as onboard recreational fishing, spearfishing, and recreational diving. This area was also evaluated as the one under the highest risk of impact, considering the current scenario of management. The most successful scenario modeling to reduce these risks was the hypothetical implementation of a 66% reduction of all activities over all QGI habitats. Despite that, the scenario simulating the application of the regulations present in the MPA management plan was enough to reduce almost half the maximum risk value. Therefore, we concluded that to provide a balance among conservation, uses, and the local economy, the application of these regulations is the better management scenario modeled for the study area. Such results provided useful information and tools for local management and decision-making in this singular marine environment, also being an example for mapping ecosystem services and modeling risks in MPAs worldwide.

Limited human access is linked to higher effectiveness in a marine sanctuary

Marine Protected Areas (MPAs) are a widely used tool for coral reefs conservation, but massive tourism activities inside MPAs worldwide can challenge their effectiveness. This study investigated the role of different levels of protection strictness (no-entry, low and high tourism-allowed zones) set for a marine sanctuary in shaping benthic cover and reef fish community structure in the richest and largest coral reef system of the Southwestern Atlantic. Reef fish community structure and benthic cover differed between protection levels. No-entry zones showed significant higher coral coverage and biomass of piscivores and herbivores than tourism-allowed zones. Highest differences were found between no-entry and high tourism intensity zones. Despite the fact that protection from fishing by itself can ensure conservation benefits, we show here that the establishment of no-entry zones improve MPAs effectiveness.

Ghost fishing impacts on hydrocorals and associated reef fish assemblages

Ghost fishing is a threat to many marine environments, as lost or discarded fishing gear (e.g., fishing lines, nets) continues to fish by entangling, damaging or killing various organisms. Among the benthic organisms that live on tropical reefs, the group probably most affected, due to their shape, are the branching corals. These corals provide refuge, foraging and breeding sites, especially for fishes and therefore impacts on coral structure could compromise the ecology of associated species. We tested if fishing lines entangled on the branching coral Millepora alcicornis would result in an increase in colony mortality, decrease in abundance and richness of fishes and changes in the behavior of associated reef fish. In the field, we estimated the volume of M. alcicornis colonies and its mortality percentages, and videos were recorded to evaluate abundance and richness of fish assemblages and fish behavior. Our results showed that coral mortality increased with increasing amounts of entangled fishing lines. Fish assemblages were similar in M. alcicornis colonies with or without entangled fishing lines. Nevertheless, we observed a significant decrease in the frequency of feeding attempts in two herbivore fish species (Acanthurus bahianus and Ophioblennius trinitatis) that play an important role in coral-reef dynamics, controlling algae abundances. Therefore, ghost fishing has negative impacts on shallow reef ecosystems, directly affecting branching corals and important coral-fish interactions. Management of tropical shallow reef environments should consider regulation and monitoring of coastal fisheries to ensure reef integrity.

Coral damage by recreational diving activities in a Marine Protected Area of India: Unaccountability leading to 'tragedy of the not so commons'

Globally, coral reefs have drastically degraded due to local and global environmental stressors. Concurrently, coral reef tourism is rapidly growing in developing economies, which is one of many anthropogenic stressors impacting reefs. At the Malvan Marine Sanctuary, a Marine Protected Area (MPA) on the West coast of India, we investigated the impact of recreational diving on the reef from 2016 to 2019. To evaluate the diver's underwater behavior, a novel approach was used, wherein the video-log broadcasting website www.youtube.com was perused. Evidential proof substantiates heavy physical damage to corals because of recreational diving activity, which may lead to the collapse of coral habitat if it continues unabated. This resource depletion ironically elevates the economy of dependents averting consequences due to lost corals, thus making this a 'tragedy' for corals which are not meant to be 'commons'. The study asserts need for proactive conservation efforts with stringent implementation and restoration initiatives in this MPA.

Ecological impacts and management strategies for recreational diving: A review

Recreational diving is an expanding branch of ecotourism that when poorly managed, may cause considerable impacts to benthic organisms. Such impacts become a matter of concern in popular diving destinations. A systematic literature review was used to verify the characteristics of divers who cause damage to reefs, the effects on benthic organisms, and the range of management interventions available. We describe the knowledge gaps, addressed challenges and propose solutions hoping to reach successful management of diving tourism industry. We identified three main challenges on recreational diving management frameworks and discussed actions to overcome such challenges. The challenges are related to (1) the lack of baseline data and long-term monitoring; (2) integration of scientific research and management; and (3) adaptive management strategies and stakeholder involvement.

Impact of student-induced disturbance on stream macroinvertebrates differs among habitat types

Environmental impacts from ecotourism and outdoor recreation activities on terrestrial and aquatic ecosystems are well-reported in the literature, but less is known regarding the impacts of outdoor environmental education activities. Student activity during stream classes may cause substrate disruption and localized impacts on stream macroinvertebrates. We hypothesized that student activity would negatively impact macroinvertebrate community structure in three habitat types (riffle, run, pool) within a site regularly used for stream classes while no impact from student activity would occur in the same three habitat types within an unused site. We addressed the hypothesis by sampling macroinvertebrates monthly for one year in the riffles, runs, and pools at the class site and the unused site within a fourth order stream in central Ohio. The results indicated reduced macroinvertebrate abundance and richness in the riffle at the class site during periods with student activity and no differences between site types during periods without student activity. No impacts of stream classes on macroinvertebrate communities were observed in runs or pools. The results suggest that environmental education organizations should avoid repetitive use of the same site for their stream classes to avoid reductions of macroinvertebrate abundance and taxa richness that can impact the students’ educational experience.

The effects of fish feeding by visitors on reef fish in a Marine Protected Area open to tourism

Abstract: Coral reef-based tourism has risen sharply across the globe, coupled with an increase in fish feeding by visitors. Studies indicate that fish feeding is one of the leading causes of changes in distribution patterns, abundance, the structure of marine fish communities, and fish behavior. The aim of this study was to determine the effect of human presence and fish feeding on the behavior of reef fish by conducting in situ experiments in tide pools in a Marine Protected Area located at the northern limit of the Abrolhos Bank in the South Atlantic Ocean. Eight feeding sessions were conducted and filmed, resulting in a total of 160 minutes of video footage. Each filming session recorded four different experimental conditions alternating between human presence, human absence, and fish feeding. Our findings suggest that fish feeding may cause changes in fish behavior, such as habituation to human presence, conditioning to fish feeding, increased aggressiveness, attacks on humans, and short-term changes in species distribution. The continuation of fish feeding over time can cause an increase in the size of the populations of species that consume food provided during feeding and consequently trigger changes in the structure of communities.

Time to stop mucking around? Impacts of underwater photography on cryptobenthic fauna found in soft sediment habitats

Scuba diving tourism is a sustainable source of income for many coastal communities, but can have negative environmental impacts if not managed effectively. Diving on soft sediment habitats, typically referred to as 'muck diving', is a growing multi-million dollar industry with a strong focus on photographing cryptobenthic fauna. We assessed how the environmental impacts of scuba divers are affected by the activity they are engaged in while diving and the habitat they dive in. To do this, we observed 66 divers on coral reefs and soft sediment habitats in Indonesia and the Philippines. We found diver activity, specifically interacting with and photographing fauna, causes greater environmental disturbances than effects caused by certification level, gender, dive experience or age. Divers touched the substrate more often while diving on soft sediment habitats than on coral reefs, but this did not result in greater environmental damage on soft sediment sites. Divers had a higher impact on the substrate and touch animals more frequently when observing or photographing cryptobenthic fauna. When using dSLR-cameras, divers spent up to five times longer interacting with fauna. With the unknown, long-term impacts on cryptobenthic fauna or soft sediment habitats, and the increasing popularity of underwater photography, we argue for the introduction of a muck diving code of conduct.