Age validation, growth, mortality, and additional population parameters of the goldband snapper (Pristipomoides multidens) off the Kimberley coast of northwestern Australia

Goldband snapper (Pristipomoides multidens) collected from commercial trap and line fishermen off the Kimberley coast of northwestern Australia were aged by examination of sectioned otoliths (sagittae).A total of 3833 P. multidens, 80–701 mm fork length (98–805 mm total length), were examined from commercial catches from 1995 to 1999. The oldest fish was estimated to be age 30+ years. Validation of age estimates was achieved with marginal increment analysis. The opaque and translucent zones were each formed once per year and are considered valid annual growth increments (the translucent zone was formed once per year between January and May). A strong link between water temperature and translucent zone formation was evident in P. multidens. The von Bertalanffy growth function was used to describe growth from length-at-age data derived from sectioned otoliths.

International Workshop for Management and Trade of Caiman yacare, Gainsville, FL, 3-5 October 2002

A workshop was held 3-5 October 2002 in Gainesville, Florida, USA to discuss management, conservation and trade in Caiman yacare. Twenty five official participants represented the four yacare range states (Argentina, Bolivia, Brazil, Paraguay), Venezuela, USA, the meeting sponsors (US Fish and Wildlife Service, CITES Secretariat, Louisiana Fur and Alligator Council), TRAFFIC Sur America and Crocodile Specialist Group. A series of country reports detailing yacare management in the four range states were distributed in Spanish and English prior to the meeting and presentations on these and on general principles of crocodilian harvest, conservation and management provided the basis for the discussions. Three working groups considered: • Requirements and field techniques for field data collection. • Requirements and techniques for regulation of harvest. • Requirements and processes for regulation of trade and export. Written reports of working groups and a plenary drafting session were finalized during the meeting and distributed, with the country reports, to participants. The workshop drafted a framework for caiman management and regulation that could be used as a template and adapted for use in each range state. The meeting agreed to convene an ad-hoc working group of range state representatives to continue discussions on the harmonization of caiman management into the future.

Revealing the appetite of the marine aquarium fish trade: the volume and biodiversity of fish imported into the United States

The aquarium trade and other wildlife consumers are at a crossroads forced by threats from global climate change and other anthropogenic stressors that have weakened coastal ecosystems. While the wildlife trade may put additional stress on coral reefs, it brings income into impoverished parts of the world and may stimulate interest in marine conservation. To better understand the influence of the trade, we must first be able to quantify coral reef fauna moving through it. Herein, we discuss the lack of a data system for monitoring the wildlife aquarium trade and analyze problems that arise when trying to monitor the trade using a system not specifically designed for this purpose. To do this, we examined an entire year of import records of marine tropical fish entering the United States in detail, and discuss the relationship between trade volume, biodiversity and introduction of non-native marine fishes. Our analyses showed that biodiversity levels are higher than previous estimates. Additionally, more than half of government importation forms have numerical or other reporting discrepancies resulting in the overestimation of trade volumes by 27%. While some commonly imported species have been introduced into the coastal waters of the USA (as expected), we also found that some uncommon species in the trade have also been introduced. This is the first study of aquarium trade imports to compare commercial invoices to government forms and provides a means to, routinely and in real time, examine the biodiversity of the trade in coral reef wildlife species.

A sudden collapse in distribution of Pacific sardine (Sardinops sagax) off southwestern Australia enables an objective re-assessment of biomass estimates

Fishery-independent estimates of spawning biomass (BSP) of the Pacific sardine (Sardinops sagax) on the south and lower west coasts of Western Australia (WA) were obtained periodically between 1991 and 1999 by using the daily egg production method (DEPM). Ichthyoplankton data collected during these surveys, specifically the presence or absence of S. sagax eggs, were used to investigate trends in the spawning area of S. sagax within each of four regions. The expectation was that trends in BSP and spawning area were positively related. With the DEPM model, estimates of BSP will change proportionally with spawning area if all other variables remain constant. The proportion of positive stations (PPS), i.e., stations with nonzero egg counts — an objective estimator of spawning area — was high for all south coast regions during the early 1990s (a period when the estimated BSP was also high) and then decreased after the mid-1990s. There was a decrease in PPS from the mid-1990s to 1999. The particularly low estimates in 1999 followed a severe epidemic mass mortality of S. sagax throughout their range across southern Australia. Deviations from the expected relationship between BSP and PPS were used to identify uncertainty around estimates of BSP. Because estimation of spawning area is subject to less sampling bias than estimation of BSP, the deviation in the relation between the two provides an objective basis for adjusting some estimates of the latter. Such an approach is particularly useful for fisheries management purposes when sampling problems are suspected to be present. The analysis of PPS undertaken from the same set of samples from which the DEPM estimate is derived will help provide information for stock assessments and for the management of purse-seine fisheries.