Cetaceans of Venezuela: Their distribution and conservation status.

Sighting, stranding, and capture records of whales and dolphins for Venezuela were assembled and analyzed to document the Venezuelan cetacean fauna and its distribution in the eastern Caribbean. An attempt was made to confirm species identification for each of the records, yielding 443 that encompass 21 species of cetaceans now confirmed to occur in Venezuelan marine, estuarine, and freshwater habitats. For each species, we report its global and local distribution, conservation status and threats, and the common names used, along with our proposal for a Spanish common name. Bryde’s whale (Balaenoptera edeni) is the most commonly reported mysticete. The long-beaked common dolphin (Delphinus capensis) is the most frequent of the odontocetes in marine waters. The boto or tonina (Inia geoffrensis) was found to be ubiquitous in the Orinoco watershed. The distribution of marine records is consistent with the pattern of productivity of Venezuelan marine waters, i.e., a concentration at 63°07′W through 65°26′W with records declining to the east and to the west. An examination of the records for all cetaceans in the Caribbean leads us to conclude that seven additional species may be present in Venezuelan waters. (PDF file contains 61 pages.)

Walk on the Water: experience of brackish rivers with children

A resource guide for teachers for 4th through 6th graders, produced as part of the Aquapeake project. Includes: background on how and why it was developed; Cycles which is a poetic expression of the wedding of natural studies with personal expression; Aout our Trip, is a tentative sketch for possible uses of the folios; Aquaria on setting up various sizes and styles of aquaria; Music, songs in word and music. (PDF contains 70 pages)

Recent Trends in the Catch of Undersized Swordfish by the U.S. Pelagic Longline Fishery

U.S. commercial vessels fishing in the Atlantic Ocean, Caribbean Sea, and the Gulf of Mexico have been subject to regulations limiting the landing of swordfish less than 25 kg whole weight since June 1991. The intent of those regulations was to reduce the mortality of immature swordfihs. Plots of fishing effort from 1990 to 1994 indicate that the regulations were effective in some areas. Fishing effort decreased after 1991 in the Venezuelan Basin, a swordfish nursery area. However, in areas close to the U.S. coastline, effort did not appear to shift away from areas where immature swordfish were discarded. To identify areas with high rates of discarding, plots were made showing areas where the number of discarded swordfish was equal to or greater than the number of fish landed.

Reproduction and recruitment of white mullet (Mugil curema) to a tropical lagoon (Margarita Island, Venezuela) as revealed by otolith microstructure

The reproductive activity and recruitment of white mullet (Mugil curema) was determined by observations of gonad development and coastal juvenile abundance from March 1992 to July 1993. Adults were collected from commercial catches at three sites in northeastern Venezuelan waters. Spawning time was determined from the observation of macroscopic gonadal stages. Coastal recruitment was determined from fish samples collected biweekly by seining in La Restinga Lagoon, Margarita Island, Venezuela. The examination of daily growth rings on the otoliths of coastal recruits was used to determine their birth date and estimate the period of successful spawning. Fish with mature gonads were present throughout the year but were less frequent between September and January when spawning individuals migrated offshore. In both years, juvenile recruitment to the lagoon was highest between March and June when high densities of 25–35 mm juveniles were observed. Back-calculated hatching-date frequency distributions revealed maximum levels of successful spawning in December–January that were significantly correlated with periods of enhanced upwelling. The relation between the timing of successful spawning and the intensity of coastal recruitment in white mullet was likely due to variations in food availability for first-feeding larvae as well as to variations in the duration of the transport of larvae shoreward as a result of varying current conditions associated with upwelling.