Growth rate estimates were obtained for elephantfish using length‐frequency and tag‐recapture data from the east coast of South Island during 1966–88. Elephantfish hatch from egg cases at about 10 cm fork length (FL) during May‐July. Females grow faster than males after their first year and growth is fastest in summer. In 1966–68, elephantfish in Pegasus Bay grew faster than in Canterbury Bight, resulting in modal length diffe...

The relationship between photosynthesis (P) and light (E) was determined for phytoplankton from the mixed layer and the deep chlorophyll maximum (DCM) at 23 stations off the east coast of New Zealand during February‐March 1995. The stations encompassed three water masses, Sub‐tropical, Sub‐antarctic and the Sub‐tropical Convergence Zone. The light‐saturated rate of photosynthesis (P max ) and slope of the light‐limited portion...

The avoidance response of the migratory juvenile stage of six species of diadromous fish to different levels of suspended solid (SS) was determined in the laboratory using a two‐choice avoidance tank. Trials were mostly conducted with resuspended sediment from the outlet of Lake Waahi, New Zealand, but a series of tests was also conducted with kaolin for comparison. Banded kokopu (Galaxias fasciatus) was the most sensitive spe...

One of the most important provisions of the U.S. Endangered Species Act precludes the “taking” of listed species on both public and private land. In past Endangered Species Act litigation, take has been broadly interpreted to include the destruction or modification of habitats as well as the direct killing of animals. This requirement created an extensive burden on private landowners to provide habitats for listed species. Thi...

The numerous tactics used to conserve biodiversity include the designation of protected areas, political change, and research and education, the latter involving paradigms such as insular biogeography and the “umbrella species concept.” In Namibia lands removed from national park status in 1970 and currently under the jurisdiction of indigenous people now contain one of the few unfenced populations of black rhinos (Diceros bic...

We explore the reaction of two resource dependent communities, west Texas ranchers and Gulf Coast oyster fishers, to scientific resource management. We examine the criteria these two social groups use to judge scientific claims, and by extension, scientific resource management. Although scientists rely on factors internal to the scientific enterprise (e.g., methodological rigor), natural resource dependent communities such as...

Over 300 native stocks of Pacific salmon, steelhead, and coastal cutthroat trout (Oncorhynchus spp.) are at risk of extinction in the Pacific Northwest. With only limited resources available for conservation and recovery, prioritization of these stocks may become necessary if meaningful measures are to be implemented. We propose criteria by which prioritization may be guided. First, we rank stocks for risk of extinction, eithe...

Genetic studies of a pupfish (Cyprinodon bovinus) endemic to a small, spring‐fed system in west Texas illustrate the potential for small introductions of non‐native species to cause large‐scale genetic changes through hybridization and genetic introgression. We performed a genetic survey (allozymes and RFLP analysis of mtDNA) of four samples of C. bovinus representing all wild populations of the species and a captive populatio...

A recent model indicating that good competitiors and abundant species face the greatest risk of extinction from habitat destruction is critically examined. The conclusions drawn from the model are shown to rely on a number of assumptions regarding the mechanism of species coexistence, the relationship between abundance and competitive ability, and spatial characteristics of habitat destruction. The generality of these assumpti...

We analyzed 30 protein‐coding loci of four southern African black rhinoceros populations in order to calculate fixation indices and genetic distances for the different populations. We concluded that one of these populations is of the subspecies Diceros bicornis bicornis and the other three of Diceros bicornis minor. No evidence of inbreeding within populations was found. F‐ statistics revealed significant differentiation betwe...

I review 10 dominant themes of ecosystem management described in the paper “What is Ecosystem Management?” (Grumbine 1994a) based on feedback received from managers actively implementing ecosystem management projects in the field. My emphasis is on practical advice from working professionals for working professionals. Key points include the importance of managing for ecological integrity, the need for social as well as scienti...

Neither the classic resource management concept of maximum sustainable yield nor the concept of sustainable development are useful to contemporary, nonanthropocentric, ecologically informed conservation biology. As an alternative, we advance an ecological definition of sustainability that is in better accord with biological conservation: meeting human needs without compromising the health of ecosystems. In addition to familiar...

The Loggerhead Shrike (Lanius ludovicianus) was once widely distributed and common over most of North America, occupying an exclusive breeding range with no other shrikes. Although it occurs in a wide variety of plant associations, this shrike is generally found in landscapes characterized by widely spaced shrubs and low trees interspersed with short grasses, forbs, and bare ground, habitats which include deserts, scrub lands,...

The demand for rhino horn has led to drastic declines in numbers of rhinos in Asia and Africa. Although all trade in rhino products has been illegal since the mid‐1970s, a lucrative illegal market flourishes and poaching continues. Horn removal from African rhinos has been conducted in Zimbabwe, Namibia, and Swaziland to deter poaching. Regeneration of horns following dehorning has created the potential for a sustainable harve...

Understanding within‐stand variation in diversity of epiphytes will provide an improved basis for producing timber while conserving biological diversity. Two 80‐ha, 50–year–old managed stands of conifers were surveyed to locate 0.4 ha putative “diversity” plots, the areas appearing most diverse in lichen epiphytes. These plots were generally located in areas made heterogeneous by canopy gaps, wolf trees (trees with large‐diame...

Evaluating the consequences and future of land protection requires broad temporal and spatial perspectives of ecological and cultural factors. We assessed the development of a system of protected areas comprising 37% of central Massachusetts in terms of changing rates and means of land protection. We compared protected areas to the surrounding matrix in terms of physical, biological, and historical features and used these resu...