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June 2006
FIELD NOTES Provided by Charles Darwin Foundation
Lichens: Nature's Environmental Sensors
Insects Tell the Story of the Extraordinary Recovery of Pinta Island
Rare Deepwater Sea Pens Rediscoverd
Netting the Small Fry to Get the Big Picture
Lichens — nature's environmental sensors
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Native loop lichen (Hypotrachyna isidiocera)
© CDF Frank Bungartz |
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Lichens - small inconspicuous plants that live on the bark of trees or even on bare rock - are sensitive environmental indicators and are often the earliest warning signs that something has gone wrong. During February and March, CDF's new lichen specialist, Dr Frank Bungartz, and visiting consultant Dr André Aptroot, explored all vegetation zones on eight different islands to update the lichen surveys last undertaken during the 1980s. As a result, a staggering 300 new species' records for Galapagos are now housed at the CDRS herbarium amongst more than 4000 specimens collected during the survey.
Lichens have recently been used to assess the impact of burning trash at the domestic waste site on Santa Cruz Island. Results indicate the urgent need to establish alternatives for waste disposal. This is a clear example of how monitoring the lichen flora in Galapagos will help give advance warning that an ecosystem might be unstable, a useful tool when balancing the needs of the human population with the conservation of Galapagos. |
Insects tell the story of the extraordinary recovery of Pinta Island
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CDF entomologist Lazaro Roque at work in the field
© CDF Lazaro Roque |
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Over 20 previously unregistered moth species, an abundance of known endemic moths, and possibly a new species of beetle were recorded by CDF entomologists and specialists from the Geneva Museum of Natural History and Wake Forest University during a March trip to the isolated and rarely visited Pinta Island. The team was there to evaluate the recovery of the island following the 2001 eradication of the feral goats that once ravaged the island, as well as to study the evolutionary biology and chemical ecology of moths. Because of their short generation time and specialized feeding habits, insects are an important indicator of the health of any ecosystem. Damaged ecosystems generally register very low levels of endemic species. However, the recent findings of large numbers of endemic species on Pinta and the impressive recovery of the native vegetation on which they depend, clearly shows there is hope for islands that have been heavily affected by introduced species to return to their natural state. |
Rare deep water sea pens rediscovered
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Deep-water endemic octocorals known as sea pens
© CDF |
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A remotely operated underwater vehicle (ROV) is changing the way that CDF marine staff carry out marine ecological monitoring. Such studies are critical to evaluate the state of marine resources and the effectiveness of the coastal zonation system established by the Galapagos National Park Service in 2000. The ROV allows researchers, who were previously restricted to safe diving depths of around 100ft, to access depths of up to 500ft, to take video footage and collect marine samples in previously uncharted habitats.
The first explorations in early April revealed an exciting rediscovery of rarely seen, deep-water endemic octocorals known as sea pens, 200ft down in Sullivan Bay off Santiago Island. Sea pens were once more abundant in the sandy bottoms of the cooler waters in the western islands but are considered extremely rare and even locally extinct since the strong El Niño event of 1981/82. Although the strange, featherlike corals disappear into the sand, making collection for positive identification difficult, initial observations suggest that these species (tentatively identified as Virgularia galapagensis, Cavernulina cf. darwini, and a third unnamed species) have persisted in cold, deep water, soft-bottom environments.
“These octocorals may represent the last remaining species that have survived strong climatic events and their collection locations may be sites for future population recovery,” says CDF oceanographer Stuart Banks. “What we are finding using the ROV emphasizes the need to better understand these fascinating habitats. New discoveries are sure to follow.” |
Netting the small fry to get the big picture
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Lobster larva collected in nuestron net
© Kathleen Newell |
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CDF and Park Service marine staff were able to test the efficacy of a variety of neuston tows (special nets designed to collect surface plankton samples) during a January trip to study the distribution and abundance of the hard-to-find lobster larvae.
The study was part of ongoing bi-institutional research being undertaken by the Galapagos National Park Service (GNPS) and the CDF aimed at understanding the population dynamics of these ecologically and commercially important species in order to strengthen resource management. “It is essential to confirm if the lobsters in Galapagos originate outside the archipelago or whether these populations are restricted to Galapagos (closed population), which has very different management implications,” said Eduardo Espinoza, the GNPS project coordinator.
The commercial spiny lobster fishery has been managed as a closed resource and, according to the fisheries' management studies, is showing signs of depletion. Key information is lacking about the lobsters' life cycle, however, and this information is necessary to create the recruitment index, improve resource management, and generate population models that will help develop sustainable management plans.
The CDF and Park team were able to traverse the Galapagos Marine Reserve traveling with visiting scientists aboard the University of Washington's School of Oceanography research vessel R/V Thompson exploring a 400-km-long section of the Galapagos mantle plume and volcanic hotspots.
Contact: comments@galapagos.org
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