Pelagic fish

List of pelagic fishes found around Bonaire and Curacao, including scientific, English, Spanish and Papiamento names. Published by the Agriculure, Husbandry and Fisheries Service of Curacao, as Agrinoticia, Piská – No.1

Suspension feeders perform a crucial role in uniting the benthic and pelagic environments in coral reef ecosystems. Of suspension feeders, sponges are one of the most highly abundant, widespread, and efficient filter-feeding organisms. However, suspension feeding in sponges is not completely understood. Previous studies have looked at the effect of temperature on pumping rate as well as the effect of particle size on retention rate. The purpose of this study was to investigate the depth-dependence of pumping rates and filtration efficiencies in two Caribbean reef sponges, Aplysina archeri and Aplysina lacunosa, at two depth profiles. Videos were taken of sponges pumping fluorescein dye to obtain pumping rates, and turbidity measurements were taken of both inhalant and exhalant water samples that were collected in situ via syringes in order to estimate filtration efficiency. The results revealed a species-specific interaction with depth for both pumping rate and filtration efficiency. Aplysina lacunosa was found to have both a faster pumping rate and increased filtration efficiency at the shallower depth, while no differences were observed across depths for A. archeri. Additionally, correlations were found between pumping rate and filtration efficiency for both species, suggesting the development of distinct filter-feeding strategies. Aplysina lacunosa had a positive correlation between pumping rate and filtration efficiency, while the correlation in A. archeri was found to be negative. Understanding the effect of depth on the filter-feeding mechanism of sponges is important to understanding the greater implications of the benthic-pelagic coupling process of sponges and suspension feeders in general.

This student research was retrieved from Physis: Journal of Marine Science XVI (Fall 2014)19: 6-12 from CIEE Bonaire.

This deskstudy gives a review of small pelagic fish species and fisheries in the Dutch Caribbean, specifically species which distributions exceed the national boundaries and where international cooperation in research and management is required. The need for this study was recently identified as a high priority action in the 2010 EEZ management plan written for the Dutch Ministry of Economic Affairs. A list of schooling pelagic species with maximum sizes of 40 cm was prepared, based on the occurrence in waters deeper than 200m, in the Dutch Caribbean and Wider Caribbean Area. As a next step the (importance for) the fisheries and biology is described with a focus on the following four species (groups): Sardines (Sardinella aurita), Scads (Carangidae), Anchovy (Engraulidae) and Flyingfishes, in particular Hirundichthys speculiger and Cheilopogon cyanopterus. A fifth group, consisting of clupeids (Clupidae) and halfbeaks (Hemiramphidae) are not truly pelagic because of their association with reefs and coastal distribution, but are locally abundant and important as bait fish.

From a management perspective, small pelagic fish in the Caribbean can be divided into three groups: (1) Species with pelagic behaviour, but coastally bound. 10-20 species, wide spread in the region, locally abundant and targeted as bait fish. This group consists of Carangidae, Clupeidae, Engraulidae and Hemiramphidae. These can be monitored in local sea going surveys because the species are more or less coastal (<less than 20 km). However, catches of small pelagic species are not monitored or surveyed, hence it is often not clear what species are involved. An appropriate survey method to monitor abundance of schooling pelagic fish is echo integration. (2) True pelagic (oceanic) species: all flying fishes, wide spread in the region. Heavily targeted as bait fish, locally for human consumption (Barbados). They are clearly crossing boundaries of EEZ’s in the region. The species involved are wide spread and due to their behaviour difficult to monitor by means of a fisheries independent, sea going survey. (3) Sardinella aurita, off shore distribution, limited to an area of upwelling off the coast of Venezuela. The monitoring of the stock is a Venezuelan appointment, although at the margins, some EEC boundaries are crossed (Columbian, Dutch).

Given the importance for the ecosystem from a Dutch perspective the main focus for further research in the Dutch EEZ, should be given to coastal pelagic species in the pelagic area’s adjacent to coastal reef zones around the archipelagos. This implies no international coordination for this group in the executional phase of the survey. The second group – flyingfishes - requires more international cooperation. This group should be surveyed within ecosystem focussed surveys, running multiple methodologies like visual observations of birds and mammals, biological sampling of fish and hydrographical observations.

The potential for a small pelagic fishery in the Dutch EEZ is discussed. Direct consumption of small pelagic fish, rather than using it in the reduction sector, is more efficient from a biological and an economical point of view. For the Dutch EEZ, as a first step a (bio-)economic study into the potential of the development of a sustainable fishery for small pelagic fish in the Dutch EEZ could be initiated. The flyingfish fishery in Barbados could be used as an example or a reference. Depending on the presence of local pelagic resources, such a study should not merely focus on flying fish but should include all small pelagic fish. The Barbados flying fish fishery could also be used as an example for a local experimental fisheries project.

Finally it is recommended to start collecting data in the pelagic area’s adjacent to coastal reef zones by yearly fisheries independent sea going surveys. The best survey technique for small pelagic fish is fisheries acoustics. However, a holistic approach, incorporating observations of multiple trophic levels, using different strategies within a single survey would be highly preferable. This means that such a survey should be combined with systematic visual observations of seabirds and cetaceans as well as the collection of zooplankton and environmental data.