Specimen collection: An essential tool

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Science  23 May 2014:
Vol. 344, Issue 6186, pp. 814-815
DOI: 10.1126/science.344.6186.814

Collecting biological specimens for scientific studies came under scrutiny when B. A. Minteer et al. [“Avoiding (re)extinction,” Perspectives, 18 April, p. 260] suggested that this practice plays a significant role in species extinctions. Based on a small number of examples (rare birds, frogs, and a few plants), the authors concluded that collection of voucher specimens is potentially harmful to many species, and that alternatives—photographs, audio recordings and nonlethal tissue sampling for DNA analysis—are sufficient to document biological diversity.


Many Alpheidae shrimps live deep in the reef and are impossible to collect nonlethally.


The isolated examples that Minteer et al. cited to demonstrate the negative impact of scientific collecting have been carefully analyzed, and none of these extinction events can be attributed to that cause (13). For example, only about 102 Great Auk specimens (Pinguinus impennis) exist today in scientific collections, many of which are skeletons obtained after extinction, whereas millions were harvested for food, oil, and feathers over millennia (1). Similarly, only nine Mexican elf owls (Micrathene whitneyi graysoni), endemic to Socorro Island, Mexico, are present in natural history collections. Field notes indicate that this species was common when specimens were collected between 1896 and 1932, and the most likely reasons for extinction around 1970 were habitat degradation and predation by invasive species (2).

Scientists have come a long way from the days of indiscriminate collecting. Modern collecting adheres to strict permitting regulations and ethics guidelines, including the general practice of collecting a number of specimens substantially below levels that would affect population demography (3, 4). The suggested alternatives to collecting specimens (photographing, recording calls, or sampling tissue nonlethally) are individually problematic, and even together cannot be used to reliably identify or describe the vast majority of Earth's biodiversity [for example, a large proportion of the world's marine biodiversity is hidden deep in its habitat (see image)]. Moreover, identification is often not the most important reason to collect voucher specimens. Studies of morphological diversity and its evolution are impossible without whole specimens. Preserved specimens also provide verifiable data points for monitoring species health, distribution, and phenotypes through time. Both historical and new collections played a key role in understanding the spread of the chytrid fungus infection, one of the greatest current threats to amphibians (5). The decision to ban dichlorodiphenyltrichloroethane (DDT) and other environmental pollutants was the result of the discovery of thinning of bird eggshells collected over an extended period (6). One of the negative effects of climate change, declining body size in animals, was only discovered with morphological data from museum specimens (7). Furthermore, IUCN Red List criteria require specific and detailed information about life history and biology (such as longevity and growth rate), especially for widely distributed species; therefore, without specimens, the extinction risk of many species cannot be properly assessed (8). Most specimens were not collected with these objectives in mind, and this is a hallmark of biological collections: They are often used in ways that the original collector never imagined. With new technologies continuing to emerge (such as stable isotope analyses, massive parallel sequencing, and CT-scan tomography), scientific collections are becoming even more important for studies of ecology, evolution, and conservation (9).

The arguments of Minteer et al. erroneously portray the critical importance of scientific collecting in a negative light and distract from the primary causes of modern extinction: habitat degradation and loss, unsustainable harvesting, and invasive species (10). It is important to distinguish protecting the lives of individuals from conserving populations and species. Individuals are lost every day to predation, natural death, and anthropogenic factors, hence it is the populations we try to save. Halting collection of voucher specimens by scientists would be detrimental not only to our understanding of Earth's diverse biota and its biological processes, but also for conservation and management efforts. Species descriptions, biodiversity inventories, and the identification of areas of endemism are just some of the basic information that can be obtained from specimens and collections-based research. Such knowledge, with its rich temporal and spatial dimensions, has proven fundamental in designing conservation areas and in making environmental impact assessments (11). These issues are particularly relevant in many developing nations, which ideally must seek a balance between the conservation of their natural (biological) resources and development. One example comes from the Bird's Head Peninsula of New Guinea, Indonesia, where the discovery and description of small endemic species—undetectable without specimen collection—directly resulted in the creation of several new protected areas and increased support for marine parks (12).

With our ever-increasing footprint, humans now affect even the most remote corners of Earth. Because an estimated 86% of species on the planet remain unknown (13), our goal should be to document biodiversity as rigorously as possible through carefully planned collections so that it can be effectively preserved and understood. Specimens from such collections and their associated data are essential for making informed decisions about management and conservation now and in the future. As a community, we advocate the utmost responsibility and care while making scientific collections (4). Furthermore, given increasing rates of habitat loss and global change, we believe that responsibly collecting voucher specimens and associated data and openly sharing this knowledge (for example, through GBIF, iDigBio, and VertNet) are more necessary today than ever before.


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