Effects Of Commercial Harvest Research Articles

Field Data and Stakeholders: Regulating the Commercial Harvest of Snapping Turtles in Maryland

Abstract Turtles are highly susceptible to the negative effects of commercial harvesting. In October 2007, the Maryland Department of Natural Resources convened a Working Group to discuss the snapping turtle (Chelydra serpentina) fishery in Maryland and to make recommendations considered necessary to maintain a sustainable fishery. We collected information on population structure and the collecting techniques used by local harvesters in the field. An increase in the minimum legal size limit from 9.5 inches (24.1 cm) in 2008 to 11 inches (27.9 cm) in 2009 resulted in more females being protected from harvesting yet significantly decreased catch per unit effort, forcing harvesters to increase collecting effort to maintain catch levels.

Effects of Commercial Harvesting on Population Characteristics and Rhizome Yield of Anemone altaica

Effects of Commercial Harvesting on Population Characteristics and Rhizome Yield of Anemone altaica. Commercial harvesting constitutes a direct threat to numerous non–timber forest products (NTFPs), but its ecological effects have not been well documented. Anemone altaica Fisch. ex C. A. Mey, a spring ephemeral plant found in temperate forests of Eurasia, is a traditional Chinese herb. Owing to medicinal value, its rhizomes have been harvested for commercial purposes in northwestern China for many years. This paper addresses the ecological effects of commercial harvesting on A. altaica populations under different harvest intensities. The results show that size–selective harvesting of rhizomes can increase population densities by asexual propagation. Currently, two– to three–year–old individuals derived from asexual propagation are the main targets of commercial harvesting. The increased demand in recent years has resulted in earlier and more intensive harvesting activities largely impacting the natural recovery of the harvested populations. For sustainable use of this traditional medicinal species, we recommend that a periodic harvest strategy of three to four years be adopted.

Effects of Commercial Harvest on Shovelnose Sturgeon Populations in the Upper Mississippi River

AbstractShovelnose sturgeon Scaphirhynchus platorynchus have become an increasingly important commercial species in the upper Mississippi River (UMR) because of the collapse of foreign sturgeon (family Acipenseridae) populations and bans on imported caviar. In response to concerns about the sustainability of the commercial shovelnose sturgeon fishery in the UMR, we undertook this study to describe the demographics of the shovelnose sturgeon population and evaluate the influence of commercial harvest on shovelnose sturgeon populations in the UMR. A total of 1,682 shovelnose sturgeon were collected from eight study pools in 2006 and 2007 (Pools 4, 7, 9, 11, 13, 14, 16, and 18). Shovelnose sturgeon from upstream pools generally had greater lengths, weights, and ages than those from downstream pools. Additionally, mortality estimates were lower in upstream pools (Pools 4, 7, 9, and 11) than in downstream pools (Pools 13, 14, 16, and 18). Linear regression suggested that the slower growth of shovelnose sturgeon is a consequence of commercial harvest in the UMR. Modeling of potential management scenarios suggested that a 685‐mm minimum length limit is necessary to prevent growth and recruitment overfishing of shovelnose sturgeon in the UMR.

Recruitment characteristics of the commercially harvested red sea urchin Strongylocentrotus franciscanus in Southern British Columbia, Canada

The test size frequencies of red sea urchin, Strongylocentrotus franciscanus (Agassiz), populations from British Columbia revealed low recruitment overall (≈9.5%) compared with populations from lower latitudes. Juvenile urchins tended to shelter under adult conspecifics. On a fine scale, i.e. over 0.5–8.0 km, high variability in recruitment was evident. Possible effects of commercial harvesting are discussed. Site-specific harvest controls based on local habitat and urchin population (size-frequency) data are desirable as a fishery management tool, but would be too costly to gather over such an extensive coastal area.