Invertebrate species represent more than 99% of animal diversity; however, they receive much less publicity and attract disproportionately minor research effort relative to vertebrates. Nonmarine mollusks (i.e., terrestrial and freshwater) are one of the most diverse and imperiled groups of animals, although not many people other than a few specialists who study the group seem to be aware of their plight. Nonmarine mollusks include a number of phylogenetically disparate lineages and species-rich assemblages that represent two molluscan classes, Bivalvia (clams and mussels) and Gastropoda (snails, slugs, and limpets). In this article we provide an overview of global nonmarine molluscan biodiversity and conservation status, including several case studies documenting the diversity and global decline of nonmarine mollusks. We conclude with a discussion of the roles that mollusks and malacologists should play in conservation, including research, conservation management strategies, and education and ou...

https://www.jstor.org/stable/10.1641/0006-3568(2004)054%5B0321:TGDONM%5D2.0.CO;2

The Global Decline of Nonmarine Mollusks

Minimizing the impact of invasive alien species (IAS) on islands and elsewhere requires researchers to provide cogent information on the environmental and socioeconomic consequences of IAS to the public and policy makers. Unfortunately, this information has not been readily available owing to a paucity of scientific research and the failure of the scientific community to make their findings readily available to decision makers. This review explores the vulnerability of islands to biological invasion, reports on environmental and socioeconomic impacts of IAS on islands and provides guidance and information on technical resources that can help minimize the effects of IAS in island ecosystems. This assessment is intended to provide a holistic perspective on island-IAS dynamics, enable biologists and social scientists to identify information gaps that warrant further research and serve as a primer for policy makers seeking to minimize the impact of IAS on island systems. Case studies have been selected to reflect the most scientifically-reliable information on the impacts of IAS on islands. Sufficient evidence has emerged to conclude that IAS are the most significant drivers of population declines and species extinctions in island ecosystems worldwide. Clearly, IAS can also have significant socioeconomic impacts directly (for example human health) and indirectly through their effects on ecosystem goods and services. These impacts are manifest at all ecological levels and affect the poorest, as well as richest, island nations. The measures needed to prevent and minimize the impacts of IAS on island ecosystems are generally known. However, many island nations and territories lack the scientific and technical information, infrastructure and human and financial resources necessary to adequately address the problems caused by IAS. Because every nation is an exporter and importer of goods and services, every nation is also a facilitator and victim of the invasion of alien species. Wealthy nations therefore need to help raise the capacity of island nations and territories to minimize the spread and impact of IAS.

/pdf/ecological-and-socioeconomic-impacts-of-invasive-alien-1l1ho38n7s.pdf

Ecological and socioeconomic impacts of invasive alien species in island ecosystems.

Foreword J. Waage. Preface. A History of Methodological, Theoretical and Empirical Approaches to Biological Control G.M. Gurr, et al. Classical Arthropod Biological Control: Measuring Success, Step By Step R.G. van Driesche, M.S. Hoddle. Success in Biological Control of Arthropods by Augmentation of Natural Enemies J.C. van Lenteren. Success in Conservation Biological Control of Arthropods G.M. Gurr, et al. Success in Biological Control of Terrestrial Molluscs G.R. Port, et al. Success in Biological Control of Aquatic Weeds by Arthropods I.W. Forno, M.H. Julien. Success in Biological Control of Terrestrial Weeds by Arthropods P. Syrett, et al. Success in Biological Control of Plant Pathogens and Nematodes by Microorganisms J.M. Whipps, K.G. Davies. Success in Biological Control of Soil-dwelling Insects by Pathogens and Nematodes T.A. Jackson, et al. Success in Biological Control of Above-ground Insects by Pathogens W.D. Gelernter, C.J. Lomer. Success in Biological Control of Weeds by Pathogens, Including Bioherbicides B.A. Auld. Success in Biological Control of Vertebrate Pests G.J. Hickling. Non-target Effects of Biological Control Agents F.G. Howarth. Synthesis: The Future Success of Biological Control S.D. Wratten, G.M. Gurr. Index.

Biological control : measures of success

Mollusks are the group most affected by extinction according to the 2007 International Union for Conservation of Nature (IUCN) Red List, despite the group having not been evaluated since 2000 and the quality of information for invertebrates being far lower than for vertebrates. Altogether 302 species and 11 subspecies are listed as extinct on the IUCN Red List. We reevaluated mollusk species listed as extinct through bibliographic research and consultation with experts. We found that the number of known mollusk extinctions is almost double that of the IUCN Red List. Marine habitats seem to have experienced few extinctions, which suggests that marine species may be less extinction prone than terrestrial and freshwater species. Some geographic and ecologic biases appeared. For instance, the majority of extinctions in freshwater occurred in the United States. More than 70% of known mollusk extinctions took place on oceanic islands, and a one-third of these extinctions may have been caused precipitously by introduction of the predatory snail Euglandina rosea. We suggest that assessment of the conservation status of invertebrate species is neglected in the IUCN Red List and not managed in the same way as for vertebrate species.

http://stoppinginvasives.org/dotAsset/d449a517-d66a-4c1d-ac49-a2e04eb95cfe.pdf

Not knowing, not recording, not listing: numerous unnoticed mollusk extinctions.

Infectious diseases are increasingly recognized as the cause of mass mortality events, population declines, and the local extirpation of wildlife species. In a number of cases, it has been hypothesized that pathogens have caused species extinctions in wildlife. However, there is only one definitively proven case of extinction by infection, and this was in a remnant captive population of a Polynesian tree snail. In this article, we review the potential involvement of infectious disease in the recent extinction of the sharp-snouted day frog Taudactylus acutirostris. Our review of available evidence suggests that a virulent pathogen of amphibians, Batrachochytrium dendrobatidis, caused a rapid, catastrophic decline of this species, from which it did not recover. We propose that this is the first case of extinction by infection of a free-ranging wildlife species where disease acted as both the proximate and ultimate cause of extinction. This highlights a probable underreporting of infectious disease as a cause of biodiversity loss historically and currently.

The Decline of the Sharp-Snouted Day Frog ( Taudactylus acutirostris ): The First Documented Case of Extinction by Infection in a Free-Ranging Wildlife Species?

Following the well documented extinctions of many species of endemic tree snail (family Partulidae) throughout French Polynesia, field surveys were undertaken on four islands in the Society archipelago to provide up to date information for the international conservation programme for this group of invertebrates These surveys have confirmed the loss of all species of Partula in the wild on the Society Islands other than Tahiti Thirty-three species have been lost from Raiatea, thereby eliminating one of the most outstanding examples of island evolutionary radiation On Huahine the disappearance of P varia and P rosea, used for making lei (shell jewellery), had an economic and social effect on the local community: many of the women of the villages lost their livelihoods, and the artisan's association folded The seven species of Partula on Moorea were extinct in the wild by the mid 1980s, terminating almost 100 years of biological research It now seems that the remnant populations of Samoana attenuata discovered only 5 years ago are the only species of partulid still surviving beyond Tahiti on the Society Island group The mixed species populations in the Te Pari area of Tahiti-Iti are still extant, but the predatory snail Euglandina rosea has now spread to the last valley on the Peninsula that did not have previous evidence of predator activity On Tahiti-Nui populations of partulid, without the predator, were found near the crest of Mount Tahiti above Orofero Valley Partulidae are clearly a highly threatened family of invertebrates, and in need of the most intense conservation focus

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/43AC50C3FF363348CE0A93A8C0CD932D/S0030605303000176a.pdf/div-class-title-from-61-species-to-five-endemic-tree-snails-of-the-society-islands-fall-prey-to-an-ill-judged-biological-control-programme-div.pdf

From 61 species to five: endemic tree snails of the Society Islands fall prey to an ill-judged biological control programme

The current distribution of endemic partulid snails on Tahiti in French Polynesia reflects the danger of ignoring expert advice and introducing an alien species into a fragile island ecosystem. The endemic tree-snail fauna of the island now faces extinction. Although the extinction of the native species of Partula (Partulidae; Polynesian tree snails) on Moorea in French Polynesia is well known in the world of conservation biology, losses on other Pacific islands are less well described. This paper presents an update on the status of partulid snail populations on Tahiti in the light of fieldwork undertaken between 1995 and 1997. Native snails still exist in good numbers in two areas, at opposite ends of the island. In other areas, sightings of single or a few individuals indicate remnant populations now on the edge of extinction. Efforts to protect these populations and others in French Polynesia are being planned in collaboration with local government authorities.

/pdf/extant-populations-of-endemic-partulids-on-tahiti-french-4qkemlby53.pdf

Eric Loeve

Papers

From 61 species to five: endemic tree snails of the Society Islands fall prey to an ill-judged biological control programme

Extant populations of endemic partulids on Tahiti, French Polynesia