Summary of " Status and Trends of Bermuda Reefs and Fishes : 2016"

 


Murdoch TJT (2018) Status and Trends of Bermuda Reefs and Fishes: 2016 Report Card. BREAM:Bermuda Reef Ecosystem Analysis and Monitoring Programme Report, Bermuda Zoological Society,Flatt’s. Bermuda. Bermuda Biodiversity Project #266

Link: Here

Synopsis

Coral reefs provide vital protection of Bermuda’s shores from storms, and attract the people who support Bermuda’s thriving tourism and international business economies. This report presents the findings of the second year of  comprehensive monitoring surveys of fish stocks and coral reef condition across the entire Bermuda Platform, since 2010, at 39 sites distributed across 4 zones: Inner Lagoon, Outer Lagoon, Rim Reef and 10-m Forereef, by the Bermuda Reef Ecosystem Analysis and Monitoring (BREAM) Long-term Ecological Monitoring (LTEM) programme. We used the newly developed IUCN GCRMN Caribbean reef monitoring protocol, and international standard for fish and reef monitoring. The GCRMN protocol focuses on various kinds of information about local reefs and reef fish populations:

1.      Fish abundance and biomass of commercially-exploited predatory fishes, plant-eating (herbivorous) fishes and other fish groups.

2.      Benthic assemblage structure: cover of hard corals, fleshy macroalgae and other sessile reef organisms.

3.      Abundance of juvenile hard corals and coral diseases that influence the future condition of reef corals.

4.      Abundance of mobile meso-faunal invertebrates such as lobsters, plant-eating sea urchins and other reef animals.

 

In this report, we utilize a four-component index of reef condition, called the Sea Life Index (SLI), which we introduced in 2016 in the report on  the “Baseline Status of Bermuda’s Reefs and Fishes” (Murdoch and Murdoch 2016). We compared our baseline data from the same 39 sites to new data collected in the summers of 2015 and 2016, using a team of trained scientific divers. Each reef was surveyed with replication using standardized scientific methods. The results of the 2016 monitoring assessment are summarized below, ranked by the strength of their potential impact.

 

Main Conclusion

The Sea Life Index (SLI) for the Bermuda reef ecosystem as a whole region, shown below, remains Fair.

 

The SLI for each reef zone are shown below. SLI, and each component factor, improves as the distance from shore of each zone increases. This implies that human factors are in part driving reef condition, and, since policy and resource management is focussed on human behaviours, that reef condition can be improved though management and conservation in ways that would improve reef health.

 


STATUS:

Critical

Poor

Fair

Good

Very Good

Positive Results 

Factor

Status

Regional Trend

Action

Sea Life Index

Fair

YES

Herbivorous Fishes – Biomass

Very Good

NO

Invasive Lionfish - Abundance

Very Good

NO

Hard Corals – Cover

Good

NO

Crustose Coralline Algae, Turfs, Bare Rock (CTB) – Cover

Good

NO

Juvenile Hard Corals

Fair

NO

 

·         Overall, the SLI is Fair, but Stable. This indicates that reef and fish health across the four zones of the region should be improved, through directed marine resource management, while the ecosystem still retains the natural capacity for improvement.

·         Herbivorous Fishes were found to be in Very Good (very abundant) and increasing condition across the region, and were seen to be in higher densities in the Outer Lagoon, Rim and 10-m Forereef zones in 2016 relative to 2015 and the Baseline surveys. Bermuda’s two decades of protection of parrotfishes, following the 1990 fish pot ban, seems to be working. Surgeonfishes protection should also be considered, since these unregulated fish species are large and abundant enough to be the target of harvest.

·         Invasive Lionfish were not observed in any of the 37 sites in 2016. This Very Good (absent) status contrasts sharply with most Caribbean countries. For example, lionfish were observed in over 25% of reef sites across the Mesoamerican region when using the same survey methods (Healthy Reefs Initiative 2017). The rarity of lionfish in Bermuda. specifically in shallow water reefs where juvenile parrotfish have their strongest impact to reef health, is very positive news. Eddy et al (2016) determined that juvenile parrotfishes are not a major component of the diet of Bermuda lionfish. Additional analysis of the BREAM LTEM data of juvenile parrotfish abundance may further illustrate the lack of ecological impact by lionfish across the shallow reef platform.

·         Hard Corals remain in Good (high) cover in 2016, with little change from 2015 or the Baseline surveys. Hard Corals rely on the other reef factors to remain resilient to change.

·         CTB was generally in Good (high) cover, but did decline on the 10-m Forereef zone. However, since Hard Corals were observed to increase in 2016 in the same zone, the reduction in CTB may be a natural consequence of this otherwise beneficial change to the 10-m Forereef habitat.

·         Juvenile Corals were Fair (moderately abundant) and unchanging over the survey periods. Positive news.

 

Negative Results

 

Factor

Status

Regional Trend

Action

Predatory Fishes – Biomass

Critical

YES

Territorial Damselfishes – Abundance

Poor

↑↑↑

YES

Herbivorous Snails & Hermit Crabs – Abundance

Critical

↓↓↓

YES

Herbivorous Sea Urchins – Abundance

Critical

YES

Coral Diseases & Bleaching – Prevalence

Poor

YES

Fleshy Macroalgae – Cover

Poor

YES

 


·         Predatory Fishes remain in Critical (very low) condition across the platform, due to overfishing. These fishes play a vital role in maintaining the condition of the ecology of Bermuda’s coral reefs. Management actions to reduce the catch and increase the protection of large and mid-sized groupers, snappers and sharks, should be a national priority.

·         Territorial Damselfish are in Poor (high) abundance in 2016, and have increased substantially and significantly since both the Baseline surveys and 2015. Their biomass has doubled in Lagoon since Baseline. This needs to be addressed by improving stocks of snappers and mid-sized groupers (i.e. meso-predatory fishes) on lagoonal reefs. We also recommend that the relationship between territorial damselfishes, the coral they harm, and the meso-predatory fishes that keep territorial damselfishes in check be assessed further. It may also be useful to close fishing on 2 to 4  lagoonal patch reefs for 2-3 years, to see if a reduction in human fishing pressure allows the recovery of meso-predatory fishes and a subsequent reduction in the abundance of coral-damaging territorial damselfishes.

·         Microherbivorous Snails and Hermit Crabs were in Critical (low) condition, declining substantially in 2015 and more so in 2016 relative to Baseline surveys. The microherbivores maintain crustose-coralline algae habitat, which is critical for the recruitment of new hard corals. An increase in predation or in mortality caused by disease or pollution may have caused the decline. Focused surveys of the important Microherbivore group should be done as soon as possible across the Rim and 10-m Forereef zones.

·         Herbivorous Sea Urchins were observed to remain in Critical (very low) condition in 2016, with an additional decline in abundance on the 10-m Forereef. It may be that predation has increased on this now rare group of sea urchins, and we recommend adding sea urchin predators such as triggerfishes to the fish assessments in future surveys. In addition, echinoderms including sea urchins often are very patchily distributed on the scales of 100-m to 10-km. Large-scale drift surveys across the Rim and 10-m Forereef zones, which document the location and extent of high-density patches of sea urchins are advised.

·         Coral Disease was seen to be Poor (high) in both the Rim and 10-m Forereef, with substantial increases in coral disease in the Rim reef zone. It is recommended that further study on the dynamics and changes in coral disease in these zones be carried out as soon as possible.

·         Fleshy Macroalgae remains in Poor (high) condition in 2016, and was seen to be significantly higher in the Inner Lagoon zone compared to Baseline and 2015. Inner Lagoonal reefs are in particularly poor condition. Further research into the ecology of these nearshore lagoonal reefs is required to determine the specific causes of damage and how to resolve them.

Recommendations for Action

The following recommendations are based on the condition of each factor (above) assessed in the project:

1.       The restoration of grouper and snapper stocks, their enhanced protection, and improved management of all predatory fishes and sharks, to prevent future declines should be a national priority.

2.       Determine whether macroalgae continues to increase in cover within the Inner Lagoon, and the causes for its increase.

3.       Further study of the dynamics and changes in coral disease in Bermuda should be carried out as soon as possible.

4.       The relationship between territorial damselfishes, the coral they harm, and the meso-predators that keep territorial damselfishes in check be assessed further. It may also be useful to close fishing on a very small number of lagoonal patch reefs for 2 to 4 years, to see if a reduction in human fishing pressure allows the recovery of meso-predatory fishes, and a subsequent reduction in the abundance of coral-damaging territorial damselfishes.

5.       Add sea urchin predators to the fish assessments in future surveys. In addition, echinoderms including sea urchins often are very patchily distributed on the scales of 100-m to 10-km. Large-scale drift surveys across the Rim and 10-m Forereef zones, which document the location and extent of high-density patches of sea urchins is advised.

6.       Focused follow-up surveys of the important Microherbivore group be undertaken as soon as possible across the Rim and 10-m Forereef zones.

Additional Recommended Management Actions or Changes to Policy

In addition to the recommendations above, we recommend that the following management strategies are implemented:

 

A: Support the Monitoring of Coral Reefs and Fishes

This report represents Bermuda’s national assessment of the condition of our coral reefs and fishes, as part of the international Global Coral Reef Monitoring Network assessment of reefs across the Caribbean. The project was partially funded by two non-government grants by the Bermuda Zoological Society and the XL-Catlin End-to-End Marine Research Grant. However, the project was only possible through the donation of a substantial amount of time and resources by the BREAM programme and the Murdoch and Gosling families.

The Bermuda Government has committed to the protection and management of Bermuda’s coral reefs and marine resources through the creation of policy and via its commitments to several local and international conventions, including the Bermuda Biodiversity Action Plan, the Convention on Biological Diversity, the Convention of Migratory Species, and the Convention of Wetlands of International Importance.

As such, future monitoring of the status and condition of fishes and coral reefs should be supported and funded, at least to some extent, by the Bermuda Government.

 

B. Support the Development of an Environmental Decision-Making Protocol

Changes in each factor assessed within this BREAM LTEM project should function as indicators that are directly linked to specific management and conservation actions. It would be preferable that Government and Non-Government stakeholders assisted in the development of an Environmental Decision-Making Protocol (EDMP) that defined what actions were available and appropriate responses to changes in the abundance or distribution or status of each of the critical reef health indicators we assess in this report. The development of an EDMP would accelerate the rate at which resource managers and conservationist could respond to problematic changes in the condition of our reefs or fish stocks, and would provide nationally accepted goals for marine environmental health and resilience.

 

C: Restoration of Predatory Fish  Populations

1.       Enhance the stocks of groupers by introducing a limited ban on the capture and sale of Black groupers during their spawning period (as we currently do with spiny lobster), based on evidence of the timing of their maximum aggregation at spawning sites.

2.       Consider bag and size limits on grey snappers, schoolmaster snappers, yellowtail snappers, graysbys and coneys.

3.       Expand our knowledge of juvenile predatory fish habitats, which are generally within the lagoon (patch reefs), along the shore (nearshore), and within enclosed bays (inshore). Many species of offshore reef fish, including predatory fish species, start life by settling as juvenile fish to coastal habitats, only to move offshore as they mature.

4.       Reduce coastal development and pollution impacts to the marine environment, as many juvenile reef fishes are found the inshore and nearshore waters first before they move to outer reef areas.

5.       Design coastal structures such as docks and breakwaters with rough surfaces or attachments, which mimic natural habitat, so that they provide additional habitat for juvenile and adult fishes.

6.       Restore coastal mangroves, rocky intertidal and seagrass habitat, which all has declined substantially in the past 75 years.

 

D. Expand Marine Spatial Protected Areas

Protected areas act as a marine resource “banks” and provide “interest” in the form of continuously available fishes for commercial and recreational harvest, through the spill-over effect, and enhanced reproductive output. We recommend the expansion in the distribution of protected areas that span the reef platform from inshore bays, along lagoonal chains of reefs, out to the forereef. These areas are juvenile habitats that are current threatened due to a lack of smaller predatory fishes and high damselfish densities. Networks of protected reefs allow fish to transition from zone to zone throughout their life cycle, by providing protected paths from nearshore habitats to the lagoon, rim and forereef.

 

E. Expand the Fishing License Programme

Recently the Fishing License programme was expanded to include recreational spear fishers. We recommend that all recreational fishers require a licence. This would include both those fishing from the shore and those using marine craft. Access to fishing activity should not be financially onerous to those with low income, however. No-cost licences to locals who use hand lines within their parish of residence could be provided so that the financially challenged retain access to fishing activities.

 

F. Recommendations for Environmental Organizations

Many of the recommended actions within this report are also within the range of issues addressed by local environmental organizations. We hope that these recommendations are adopted by local stakeholders. We offer our services in providing the members of local non-government organizations with lectures and information that supports the sharing of information on how to better manage and improve the condition of Bermuda’s coral reefs.


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