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What Doesn’t Kill You Makes You Wary? Effect of Repeated Culling on the Behaviour of an Invasive Predator

Researchers in the Bahamas found that lionfish on culled reefs altered their behavior. They were less active and hid deeper during the day, when culling took place. This led them to hunt more often during dawn and dusk, which is also when their prey are more active. Researchers are not sure whether this shift in behavior is learned (lionfish have learned to perceive the threat of divers hunting for them) or evolutionary (the bold lionfish are being culled, leaving the shy and more hidden ones). This has management implications because if they are learning to hide it is important to cull them at longer intervals, so that they ‘forget’ their fear of divers. If their behavior is evolutionary, and the more bold lionfish are being hunted and killed, this could have positive benefits for conservation efforts. The remaining population would have a lower fitness because shyer predators capture fewer prey.

Author: Cote, I.S., E.S. Darling, L. Malpica-Cruz, N.S. Smith, S.J. Green, J. Curtis-Quick, and C. Layman
Year: 2014
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PLoS ONE 9(4): e94248. doi:10.1371/journal.pone.0094248

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Florida – Ecological Restoration


Coral Propagation and Restoration to Aid the Recovery of Populations of Acropora Corals Throughout Florida and the U.S. Virgin Islands

Location
Florida Keys and US Virgin Islands (St. Croix and St. Thomas)

Nursery set-up. © Meaghan Johnson (TNC)

Nursery set-up. © Meaghan Johnson/TNC

The Challenge
Since the 1970s, two reef-building corals, staghorn (Acropora cervicornis) and elkhorn (Acropora palmata), have experienced a significant and catastrophic decline throughout Florida and the Caribbean due to a number of causes, including disease, coral bleaching, hurricanes, and localized anthropogenic impacts. Both species were listed by the National Oceanic and Atmospheric Administration’s National Marine Fisheries Service (NMFS) as threatened under the Endangered Species Act (ESA) in 2006, after an extensive review of remaining population sizes. NMFS has proposed that they be listed as endangered species; a final determination of their status has not yet been made.

In 2009, The Nature Conservancy (TNC) received a $3.3 million, 3-year grant from the National Oceanic and Atmospheric Administration (NOAA) through the American Recovery and Reinvestment Act (ARRA) to expand on existing acroporid restoration work. NOAA has continued to fund the project through the TNC-NOAA Community-Based Habitat Restoration grant program through 2015. The project is a regional effort designed to aid the recovery of populations of Acropora corals throughout Florida and the USVI, and to provide social and economic benefits for local communities in addition to long-term ecological habitat improvements.

The short-term habitat restoration goal of the ARRA project was to enhance coral populations at 34 degraded coral reefs in 8 distinct areas of the coral reef ecosystems of Florida and the USVI by propagating Acropora corals in seafloor nurseries and then transplanting nursery-grown coral fragments to depleted reef sites. A total of 5,500 corals were outplanted to 36 sites under ARRA funding and an additional 2,000 have been outplanted so far under the new funding.

Actions Taken

History
In 2000, Ken Nedimyer of SeaLife and his daughter began to propagate A. cervicornis coral fragments as part of a 4-H Youth Development project for her high school. Nedimyer later approached TNC and the Florida Keys National Marine Sanctuary about using the fragments for coral restoration purposes. In 2004, TNC and Nedimyer received funding through the NOAA-TNC Community-based Habitat Restoration Grant Program to initiate a pilot study in which corals were grown in the nursery and outplanted to Key Largo reefs after a year.

This pilot project was successful and in 2006 led to an expansion project, funded through the same source. New nurseries were built in Broward County by Nova Southeastern University, Biscayne National Park by University of Miami, and the Lower Keys by Mote Marine Laboratory. Coral fragments for this project were collected from the wild. These fragments were propagated in the nursery for a year and monitored extensively for growth and survivorship. They were then outplanted in each region across reef zones and monitored for growth and survivorship. In 2009, when ARRA monies became available, the groundwork had already been laid to significantly increase the scope of this project. The project expanded to include nurseries along the entire Florida reef tract and in St. Croix and St. Thomas, USVI.

Coral Nurseries
With growth rates faster than any other Caribbean coral species and asexual fragmentation as the dominant form of reproduction, Acropora corals can be efficiently propagated using low-tech in-water nurseries. Strategically located where natural and human threats are low, in-water nurseries provide a stable setting for highly vulnerable tiny coral fragments to grow and thrive when properly maintained by local coral farmers. When coupled with advanced genetics, nursery-reared corals with high survivorship potential (typically 1 year or more in age) can be outplanted to adjacent degraded reefs to enhance the genetic diversity and population size of remnant coral populations.

Nursery set-up and monitoring. Photo © Liz Larson (Nova)

Nursery set-up and monitoring. © Liz Larson/Nova

To start each nursery, three fragments (10 cm or smaller) were clipped from 20 isolated wild staghorn colonies within each of the six Florida sub-regions and relocated to the established nursery in each sub-region. In addition, natural fragments that were found detached from the parent colony and unlikely to survive on their own, known as fragments of opportunity, were collected and further fragmented. In the USVI, only fragments of opportunity were collected per permit requirements. As nursery fragments grow, they are clipped to create additional fragments, all of which are marked with unique identification codes so they can be traced back to their parent colony.

Nursery sites are monitored (for presence/absence of disease, bleaching, breakage, predation, and survivorship) and maintained (algae removal as needed). The genotypic identity of all wild parent colonies from each sub-region was determined after collection. This genetic marker is a valuable tool that allows long-term tracking of recruitment and proliferation resulting from the restoration sites across Florida and the USVI. This information was added into the existing genetic library for the species to help determine genetic relationships across Florida and Caribbean sub-regions. All genotyping is conducted by Penn State University.

Documenting growth on outplantings. ᄅ Meaghan Johnson/TNC

Documenting growth on outplantings. © Meaghan Johnson/TNC

A total of about 6,500 individual Acropora colonies that have been raised in the nurseries have now been outplanted back to degraded reefs throughout Florida and the USVI. Corals were outplanted at sites that have conditions conducive to their survival. Different genotypes were outplanted within arrays at each site to maximize the chances of successful cross-fertilization once the corals reach spawning size (likely in 2-5 years).

How successful has it been?
Due to the success of this project, a guide has been produced for other similar projects in the region. The Caribbean Acropora Restoration Guide: Best Practices for Propagation and Population Enhancement was produced in late 2011. This guide was written by many of the partners on the project and shares lessons learned and best practices for the restoration of Acropora in the Caribbean. Some successes of the project include:

  • Approximately 50,000 coral colonies are being maintained across 16 nurseries.
  • Fragments being maintained in the nursery represent at least 98 different genotypes.
  • This project has been taken from a small pilot study to a larger scale, high production level in about 10 years.
  • Project partners are testing a variety of techniques to help improve survivorship and growth rates with the idea that more efficiency in the nurseries leads to more restoration work on reefs. This is an important next step in this work to ensure that the outplanting is completed in the most efficient and successful way possible.

 

Lessons Learned and Recommendations
This project represents a partnership between many individuals from universities, non-profits organizations, and government agencies. Working with this diverse group of partners requires open lines of communication and regular check-ins. Quarterly conference calls have helped keep everyone on the same page and allowed nursery managers the chance to communicate directly with each other. Also, nursery visits and occasional face-to-face meetings keep partners accountable and engaged.

 

Funding Summary
American Recovery and Reinvestment Act

Lead Organizations
The Nature Conservancy, Florida Keys Program

Partners
The Nature Conservancy
Coral Restoration Foundation
National Marine Sanctuary Advisory Council
Mote Marine Laboratory
University of Miami Rosenstiel School of Marine & Atmospheric Science
Nova Southeastern University
Biscayne National Park
Dry Tortugas National Park
Florida Keys National Marine Sanctuary
Southeast Florida Coral Reef Initiative
Broward County Environmental Protection and Growth Management Department
NOAA National Marine Fisheries Service
Florida Fish and Wildlife Conservation Commission
Pennsylvania State University
University of the Virgin Islands, Center for Marine Environmental Studies

Resources
Caribbean Acropora Restoration Guide, 2011 (pdf)

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Tonga – Land-Based Pollution


Coastal Reforestation in Tonga to Protect Agricultural Areas and Coastlines

Location
Houma, southwest Tongatapu Island, Kingdom of Tonga

The Challenge
In large areas of Tonga, most of the original forest cover has been removed for timber, firewood or agricultural expansion. Tongan farmers traditionally protected coastal forests as a buffer between their farms and the sea to reduce salt spray, saltwater intrusion, and wind damage from storms and cyclones. However, during the past 25 to 50 years, these forests have been cleared to extend farms seaward and take valuable timber. The deforestation has exposed shorelines, accelerated coastal erosion, reduced suitable timber for construction and firewood, and resulted in the loss of medicinal, handicraft, and other useful plants.

Case Study Tonga Reforestation 2

The project site was Houma (southwest Tongatapu): a rocky, uplifted windward limestone area, with a raised limestone terrace and a fringing coral reef that drops off to the deep ocean. © Randy Thaman

This was particularly serious around Houma on the southwest coast of Tongatapu, the largest and most populated island in Tonga, where farms and grasslands expanded towards the coast, and traditional agroforestry trees were removed. Cattle, horses and especially pigs, and the indiscriminate use of fire to prepare gardens have also damaged these forests. These losses have resulted in drastic declines in agricultural productivity and associated biodiversity; some farms have been abandoned due to the increased wind and salt spray.

The coastal lands of many other small island states are seriously threatened by coastal erosion and increasing salination, which are exacerbated by rising sea levels. The erosion can be particularly serious if the natural coastal vegetation has been removed, which leads to seawater contamination and increasing wind damage to coconut plantations, food gardens and particularly, to freshwater wells. Accelerated erosion also damages nearby coral reefs.

Actions Taken
The Tonga Coastal Protection and Reforestation Project was implemented by the Ministry of Agriculture and Forestry (MAF) and partners in the mid-1990s to address these problems. The primary objectives were to: develop and implement an effective model for coastal reforestation near the Blow Holes at Houma, and develop effective community-based programs to promote coastal reforestation and protection at community and landowner levels.

As a first step, the MAF assessed many indigenous coastal species to find the best local trees and shrubs to plant along the coastal zone. They examined previous propagation projects looking for salt- and wind-tolerant plants, particularly important food and timber trees, or other trees with cultural significance such as those that are used medicinally or for woodcarving. Some of the species selected and used include: Casuarina equisetifolia which is successful as a windbreak, coconut palms, Pandanus tectorius, Hibiscus tiliaceus, Excoecaria agallocha, Calophyllum inophyllum, Hernandia nymphaeifolia, Terminalia catappa, Tournefortia argentea, Barringtonia asiatica, and Neisosperma oppositifolium. Other indigenous species that show promise for enrichment include the high-value carving wood and multi-purpose trees, Thespesia populnea, Cordia subcordata, Guettarda speciosa, Xylocarpus moluccensis, and sandalwood (Santalum yasi), which have all been historically selectively removed from Tonga’s coastal forests.

The project site was then marked out and manually cleared to remove Guinea grass (Panicum maximum) and other shrubby vegetation in order to reduce wild fires, which damaged previous re-vegetation projects in Tonga. A 5 m wide firebreak was cleared along the land side and planted with cassava (manioke) and other crops to keep out the Guinea grasses and prevent people from trampling or driving over the young trees.

Case Study Tonga Reforestation 3

View of plants double row Casuarina windbreak on inner margin of the reforestation area forest. © Randy Thaman

A three-phase approach was used for reforestation: First, fast-growing pioneer species were planted to provide shade and shelter from the wind, with Casuarinas planted in two staggered rows five meters apart on the land adjacent to farms. Large numbers of Casuarinas can be grown easily from seed; they fix nitrogen, are useful as firewood and grow rapidly to form effective wind breaks. Thirty different native coastal tree species were also planted on the seaward side of the Casuarinas. Secondly, after about 6 months, less-tolerant, but preferred species were planted in the shelter of the pioneers. Finally, they focused on hard-to-propagate species to increase diversity matching that of the original forest.

A concerted awareness-raising program on coastal reforestation was also implemented with the local community. The program focused on the need for maintenance of the newly planted trees. This included: frequent weeding to prevent overgrowth by grasses, shrubs and vines and to reduce the fuel for wildfires and the maintenance of firebreaks; the protection of pre-existing mature trees within the planted area; and control of free-ranging livestock, particularly pigs, cattle and horses.

Understory forest. Photo: Randy Thaman.

Understory forest. © Randy Thaman

How Successful Has it Been?
The coastal reforestation project in Houma was very successful in re-establishing a viable forest and windbreak. By 2011, the forest was fully grown with the double row of Casuarinas forming a wall along the coast and protecting the farms and many other coastal trees in this multi-species forest.

  • About 25,000 seedlings and saplings from 30 indigenous species were planted along 2 km of coastline in 2.4 hectares, mostly in a narrow band 12 m wide.
  • Approximately 80% had survived after 2 years, which was more than had been expected and a credit to community-based management of the project.
  • Cyclone Hina in March 1997 caused no damage to trees, except snapping off the upper crown of some Casuarinas.
  • The community played a very positive and critical role in the project through preparing, planting, and maintaining the site.

A limiting factor for reforestation on Tonga is the legal definition of the coastal area, “the area between high tide and 50 feet (15.4 m) inland,” but local boundary markers can vary considerably. This is virtually the only land owned and controlled by the Government; thus part of the Houma site was within the coastal zone, and the rest within the estate of village chiefs. No reforestation land was in farmers’ allotments, but the coastal forests were considered to be common property for firewood, medicinal plants, wood for carving and building. Thus the agreement from the community and chiefs to the tree planting project and allowing the forest to grow was and remains a critical factor to project success.

This project has shown that coastal reforestation is a very feasible and practical activity for communities to protect their land from sea-level rise, climate variability, and extreme events (such as tsunamis and cyclones).

Lessons Learned and Recommendations
Lessons learned and key recommendations include:

  • Coastal forest protection should be a high priority for small island communities, particularly with the threat of sea level rise and increasing extreme events. Protecting original coastal forests is easier and more cost-effective than re-establishing a degraded forest
  • Using local salt-tolerant species is a cost-effective, low-tech method for coastal reforestation to protect coastal lands and communities from natural disasters and sea-level rise, and to increase food production and promote livelihood security
  • Involving traditional leadership and identifying a ‘champion’ to raise awareness in communities for a project can enhance success. The project was proposed by the traditional chief from Houma (who was also the Prime Minister) which greatly increased stakeholder buy-in to the effort from the beginning
  • National legislation is needed to support community projects in the coastal commons to reduce  coastal forest degradation, shoreline erosion, reduce sedimentation on reefs and to protect threatened marine and land animals, such as sea turtles, sea birds and land crabs, for which coastal littoral forests are their main habitat
  • Before starting, it is essential to understand traditional ownership rights and customary (‘usufruct’) rights to resources on common land
  • Planting cassava and other food crops in the fire break was successful because people were able to use their labor to reduce the fire threat through weeding while at the same time growing valuable crops
  • Selecting the most appropriate multipurpose trees is important to gain community support, this project used over 30 indigenous species all of which are culturally valuable in Tonga
  • Coastal reforestation is a long-term effort. It is critical when designing a coastal reforestation project to provide enough time to allow a three-phase coastal reforestation (pioneer species, non-pioneer species, and high forest biodiversity enrichment planting). Short-term projects often fail, which results in a lack of confidence and support from local communities
  • Regular maintenance is essential to prevent grasses, weeds and smothering vines, and to reduce the amount of fuel for fires. This was done by the Forestry staff who were assisted by the Houma community
  • Protection from free-ranging livestock is essential and may require fencing
  • Coastal reforestation is a very practical activity for communities to protect their land from sea-level rise, climate variability and extreme events (such as tsunamis, cyclones and excessively high tides and waves
  • Protecting original multi-species coastal forests is easier and more cost-effective than re-establishing or enriching a degraded forest


Funding Summary
Secretariat of the Pacific Regional Environmental Program – $10,000 (US)

Lead Organizations
Tonga Ministry of Agriculture, Fisheries and Forestry

Contacts
Randy Thaman, University of the South Pacific, Fiji; thaman_r@usp.ac.fj
Andrew Smith, WWF, Australia; asmith@wwf.org.au
Tevita Faka’oso, Forestry division, Kingdom of Tonga; foresto@kalianet.to

Partners
Australia Aid (AusAid)
Secretariat of the Pacific Regional Environmental Program (SPREP)
The University of the South Pacific
The Nature Conservancy
The Houma local community

Resources
This case study was written by Randy Thaman, Andrew Smith, and Tevita Faka’osi, Case Study #22 from the following publication: Wilkinson, C., Brodie, J. (2011). Catchment Management and Coral Reef Conservation: A Practical Guide for coastal Resource Managers to Reduce Damage from Catchment Areas Based on Best Practice Case Studies (pdf). Global Coral Reef Monitoring Network and Reef and Rainforest Research Centre Townsville, Australia, 120 P.

 

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Global Assessment of the Status of Coral Reef Herbivorous Fishes: Evidence for Fishing Effects

The authors conducted a large-scale synthesis of data to assess the global status of herbivorous fish. They found much higher biomass (2 times higher) in un-fished areas, and also much higher biomass in certain regions (central Pacific) compared to the Caribbean. They find that functional group biomass is a more accurate way to measure the status of herbivorous fishes as opposed to abundance. The browsers who consume macroalgae and are most important in preventing a coral-algal phase shift are unfortunately also most succeptible to fishing. Their management recommendations are to manage herbivore populations to be much larger than they would be naturallly in order to control algal abundance on degraded reefs, since they assume that reefs have much more algae present than in the past. They also recommend more focus on herbivore assemblages and managing for both biomass and composition of key groups rather than just on population.

Author: Edwards C.B., A.M Friedlander, A.G. Green, M.J. Hardt, E. Sala, H.P. Sweatman, I.D. Williams, B. Zgliczynski, S.A. Sandin, and J.E. Smith
Year: 2013

View Abstract
Email for the full article: resilience@tnc.org

Proceedings of the Royal Society B 281(1774): doi:10.1098/rspb.2013.1835

 

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Caribbean Acropora Restoration Guide: Best Practices for Propagation and Population Enhancement

This practical guide for coral reef managers and practitioners provides best practice methods for Acropora coral restoration projects to ensure maximum propagation and survival. This guide, which is based on scientific, in-field experiences gathered by Nature Conservancy staff and partners, begins with a detailed account of the case for restoration activities to increase the population of acroporid corals.

It provides in-depth detail into the biology of acroporid corals, best practices for coral gardening methodology, including coral fragment collection, nursery set-up and operations, and coral propagule out-plant practices. It also includes several case studies from throughout the Caribbean region on documented successes and lessons learned. This guidebook is the complete summary of current, up-to-date science on coral restoration

Author: Johnson, M.E., C. Lustic, E. Bartels, I.B. Baums, D.S. Gilliam, L. Larson, D. Lirman, M.W. Miller, K. Nedimyer, and S. Schopmeyer
Year: 2011
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The Nature Conservancy

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