Search the SPREP Catalogue

7 result(s) found.

Sort by

Publication Year
Sort results by
Created
Sort results by
Updated
Sort results by

You searched for

Tags / Keywords seaweed
X
Tags / Keywords rabbits
X

Tuvalu national biodiversity strategy and action plan: fifth national report to the convention on biological diversity.

Available Online

Alefaio, S

Falega, E

Penivao, F

Saitala, M

Teakau, F

Tekenene, M

Thaman, R

The isolated, small, low-lying resource-poor atolls of Tuvalu are clearly on the frontline against climate change, the escalating impacts natural disasters and declining food, health and energy security.

Observations of a rapid decline in invasive macroalgal cover linked to green turtle grazing in Hawaiian marine reserve

Available Online

Bahr, Keisha D.

Balazs, George H.

Coffey, Daniel M.

Rodgers, Ku'ulei

Since the 1950's, 19 algal species were intentionally (e.g., aquaculture food) and/or accidentally (e.g., ballast water) introduced into Hawaii (Glenn and Doty 1990).

Methods for monitoring invertebrate response to vertebrate eradication

Island and Ocean Ecosystems, BRB

Available Online

Houghton, M.

Shaw, J.

Terauds, A.

Once an island vertebrate eradication is deemed successful, it is typically assumed that ecosystem recovery will follow. To date, most post-eradication monitoring focuses on the recovery of key threatened or charismatic species, such as seabirds. Little attention has been given to monitoring and quantifying the response of invertebrate communities. Rabbits (Oryctolagus cuniculus), house mice (Mus musculus), and ship rats (Rattus rattus) impacted sub-Antarctic Macquarie Island for over 140 years, with wide ranging ecosystem impacts. In 2014, the eradication of rabbits and rodents was o?cially declared successful. To determine whether management objectives are being met, we are investigating the response of invertebrate communities to pest eradication, using both historic data and contemporary surveys to track changes over space and time. To achieve this, we have developed a survey strategy that is e?ective and e?cient. Here we report on the merits of utilising a variety of invertebrate trapping methodologies to establish current baselines for future invertebrate monitoring. We identify sampling techniques that are most e?ective for speci?c groups of taxa, particularly those of interest to post-eradication monitoring, and how the implementation of such methods can improve and facilitate e?ective post-eradication monitoring of invertebrates.

The Rangitoto and Motutapu pest eradication - a feasibility study.

Available Online

Griffiths, Richard.

Towns, David.

The eradication of the seven remaining animal pest species remaining on Rangitoto and Motutapu was announced by the Prime Minister and Minister of Conservation in June 2006. With stoats, cats, hedgehogs, rabbits, mice and two species of rats spread across an area of 3842ha, the proposed project is the most challenging and complex island pest eradication the Department of Conservation (DOC) has ever attempted. To better understand the scale and complexity of the project, a feasibility study was undertaken. This study considered the ecological, economic and social context of the project to allow an informed decision to be made on whether or not to commit resources to further eradication planning. This document outlines the findings of the feasibility study and concludes that while a number of contingencies exist within the project, the proposed eradication is not only feasible, but has many significant benefits. No single precedent exists on which this project can be modelled and information from a wide range of sources has been required. Previous eradication and control programmes have been reviewed in conjunction with what is known about the behaviour and biology of the target species. In some cases, where information has not been available and could not be inferred, trials have been undertaken. The document has been reviewed by a number of experts both within New Zealand and overseas including DOCs Island Eradication Advisory Group. Consultation has also been undertaken with all of the islands key stakeholders and communities of interest. Comments from all of these parties have been reflected in the report. Rangitoto is an iconic Scenic Reserve located just 9km from downtown Auckland City. The island is internationally significant both for its ecology and geology and is an extremely popular visitor destination served by regular ferry services. Motutapu, a Recreation Reserve, is connected to and positioned immediately to the east of Rangitoto. The island, currently managed as a pastoral farm, is noted for its extensive archaeological record but retains a diverse range of habitat types and is the focus of a community-led restoration programme. In addressing the question, can it be done? particular attention has been paid to mice, ship rats, hedgehogs and rabbits as eradication of these species on the scale of Rangitoto and Motutapu has never been attempted. Preventing reinvasion on such highly accessible and intensively visited islands is also an enormous undertaking. It is accepted, that of all the target species, mice present the greatest risk of failure. However, while a number of mouse eradications around the world have failed, all ten attempts on islands beyond the swimming range of mice that have followed current Departmental best practice have been successful, providing confidence in the method. Rangitoto and Motutapu are a significant step up from previous operations in terms of scale but are also the logical next step to apply current techniques. Despite the unprecedented elements within the project, it is considered that the key dependencies on which eradication success relies can be met for the species targeted. Preventing reinvasion is perhaps the most important consideration of the feasibility study and the one that will ultimately determine the fate of the project. Achieving an adequate level of protection for the islands hinges heavily on changing the behaviour of all 100,000 visitors that arrive on an annual basis. Without this any investments made in removing pests will be wasted. Bringing these changes about appears possible but is contingent on a number of commitments and actions that must be put in place by both DOC and its key partners. The feasibility study also addresses what the project will take to complete and attempts to identify as many of the planning issues as possible to enable the project to be properly sized. It explores the techniques that must be used, the resources that will be required and the timeframe over which they need to be deployed. While this eradication project is the most challenging and complex to be undertaken by DOC, it also presents a significant opportunity to improve our current understanding of eradication theory and practice. If successful, the project offers outstanding benefits for conservation. The recovery of locally and nationally endangered species, the creation of a stepping stone for wildlife movement between the Hauraki Gulf and the Auckland isthmus, the potential for advocacy and education, and increased recreation and economic opportunities are just some of the likely gains. The study has shown that this project is feasible, but also that there are many significant reasons why it should proceed.

Introduced rats indirectly change marine rocky intertidal communities from algae- to invertebrate-dominated

Island and Ocean Ecosystems, BRB

Available Online

Croll, Donald A.

Kurle, Carolyn M.

Tershy, Bernie R.

It is widely recognized that trophic interactions structure ecological communities, but their effects are usually only demonstrated on a small scale. As a result, landscape-level documentations of trophic cascades that alter entire communities are scarce. Islands invaded by animals provide natural experiment opportunities both to measure general trophic effects across large spatial scales and to etermine the trophic roles of invasive species within native ecosystems. Studies addressing the trophic interactions of invasive species most often focus on their direct effects. To investigate both the presence of a landscape-level trophic cascade and the direct and indirect effects of an invasive species, we examined the impacts of Norway rats (Rattus norvegicus) introduced to the Aleutian Islands on marine bird densities and marine rocky intertidal community structures through surveys conducted on invaded and rat-free islands throughout the entire 1,900-km archipelago. Densities of birds that forage in the intertidal were higher on islands without rats. Marine intertidal invertebrates were more abundant on islands with rats, whereas fleshy algal cover was reduced. Our results demonstrate that invasive rats directly reduce bird densities through predation and significantly affect invertebrate and marine algal abundance in the rocky intertidal indirectly via a cross-community trophic cascade, unexpectedly changing the intertidal community structure from an algae- to an invertebrate-dominated system.

Report on the distribution of the introduced seaweeds (Codium arenicola and Spatoglossum macrodontum) and the distribution and density of the crown of thorns starfish (Acanthaster planci) Reports 1 & 2 in Samoa

Island and Ocean Ecosystems, BRB

Available Online

Division of Environment & Conservation

Marine Conservation Section

Ministry of Natural Resources

An initial survey of the marine environment carried out in 2008 byDr.Posa Skelton and the Marine Conservation Section of the Division of Environment and Conservation, assessed selected sites for the presence of introduced species and the potential impacts on the marine environment. Surveys were conducted around the Apia harbour, Mulinuu and the Palolo Deep Marine Reserve- a total of eleven (11) sites. Findings from this initial assessment confirmed the presence of introduced species that were potentially invasive. This included two introduced seaweeds, Codiumarenicolaand Spatoglossummacroduntum that were observed distributed and well established across these sites.

Seaweeds of American Samoa

Available Online

Posa A. Skelton

This study provides the latest, up-to-date information on the diversity of marine plants (algae and seagrasses) of American Samoa. A general introduction to marine plants is provided, with observations on the flora of the islands. An illustrated guide to 67 macroalgae and seagrasses is provided in this report. The surveys covered 26 sites from four inhabited islands Tutuila, Aunuu, Ofu and Olosega and two smaller uninhabited islands Nuutele and Nuusilaelae. The habitats surveyed include subtidal sites to 20-m depth, inter tidal and the spray or splash zone. It also included surveys of relatively pristine coral reefs as well as high impact areas such as the inner Pago Pago Harbor. Two separate surveys, both over a two-week period in October 2002 and September 2003 were carried out and the final results are reported herein. A total of 635 specimens were analyzed and 239 algal and seagrass species were enumerated. The red algae (Rhodophyta) had the highest number of species with 133 identified. The green algae (Chlorophyta) had 60 species, the brown algae (Phaeophyta) had 29, and the blue-green (Cyanophyta) 27; only two seagrass species were found. This study showed that the flora of American Samoa is diverse, and that what is recorded reflects about 60% of the potential flora. The most diverse site was Utulei with 56 species; a site located near the Pago Pago Harbor entrance. Other notable diverse sites include the Fagatele National Marine Sanctuary with 50 species, Fagasa (44), Mafafa (36), Aua (32), and Onososopo and Fagaalu both with 31 species. The least diverse sites were the docks and the smaller Nuusilaelae Island. This is attributed to the limited collections from these sites for safety reasons. There are no substantiated records of endemic algae or seagrasses from American Samoa. Two species recorded by the American phycologist, William Setchell in 1924 (Sargassum fonanonense and Sargassum anapense) need more studies to verify their endemicity, as similar species have been recorded in the neighboring Western Samoa islands, where they are known under different names. Four algae are considered to be recently introduced into the American Samoan flora. Halymenia durvillei and Caulerpa serrulata may have been introduced from Apia Harbor, Western Samoa, whereas Grateloupia filicina and Codium mamillosum may have been introduced from places beyond the Archipelago. Although only single specimens were collected for the latter two algae, it is prudent that monitoring and surveys must be maintained to keep abreast of any potential impacts. The flora of American Samoa fits in with the biogeographic theory of decreasing diversity away from the Indo-Pacific centre of biodiversity. The 222 species of red, green and brown algae is well above those of the Cook Islands (67) and the Easter Islands (134), but below that of French Polynesia (308). The reason for this disparity is attributed to the intensity of collections. The diversity of American Samoan seagrasses and algae are better known than those of neighboring island countries. To allow for a continuous buildup and maintenance of this knowledge the following observations and recommendations are made.

www.sprep.org © 2021 - 2024. All rights reserved