Marine parasites as biological tags in South American Atlantic waters, current status and perspectives

Abstract

Many marine fisheries in South American Atlantic coasts (SAAC) are threatened by overfishing and under serious risk of collapsing. The SAAC comprises a diversity of environments, possesses a complex oceanography and harbours a vast biodiversity that provide an enormous potential for using parasites as biological tags for fish stock delineation, a prerequisite for the implementation of control and management plans. Here, their use in the SAAC is reviewed. Main evidence is derived from northern Argentine waters, where fish parasite assemblages are dominated by larval helminth species that share a low specificity, long persistence and trophic transmission, parasitizing almost indiscriminately all available fish species. The advantages and constraints of such a combination of characteristics are analysed and recommendations are given for future research. Shifting the focus from fish/parasite populations to communities allows expanding the concept of biological tags from local to regional scales, providing essential information to delineate ecosystem boundaries for host communities. This new concept arose as a powerful tool to help the implementation of ecosystem-based approaches to fisheries management, the new paradigm for fisheries science. Holistic approaches, including parasites as biological tags for stock delineation will render valuable information to help insure fisheries and marine ecosystems against further depletion and collapse.

Parasitological evidence of stocks of Paralichthys isosceles (Pleuronectiformes: Paralichthyidae) at small and large geographical scales in South American Atlantic coasts

“…in the same hosts, except for U. brasiliensis possibly due to the smaller size of Brazilian specimens. These recurrent patterns of suitable parasite tags across host species in the southwestern Atlantic reinforce previous studies in this region showing that parasite assemblages can be used as ecosystem indicators to characterize hosts living if different zoogeographical provinces (Cantatore and Timi, 2015) and, as suggested by Pereira et al (2014) for studies at larger spatial scales, as indicators of ecoregions within zoogeographical provinces.…”

“…Jaccard and Bray-Curtis indexes as the similarity measurements, respectively. Host length was introduces as a covariable (ANCOVA model) because parasites, especially long-lived ones, tend to accumulate as hosts grow, thus producing ontogenetic changes in the structure of parasite communities; and therefore fish length must be taken into account as a potential confounding variable in the interpretation of spatial patterns and stock structure when samples are not homogeneous in terms of fish size (Cantatore and Timi, 2015). The structures of parasite infracommunities between samples (1 × 2 factorial design, 'locality' as fixed factor) were compared, and the main effects were tested after 9999 permutations.…”

“…Furthermore, the inclusion of parasites in holistic approaches involving a broad spectrum of complementary techniques is increasingly recommended in stock identification studies (Begg and Waldman, 1999;Baldwin et al, 2012;Catalano et al, 2014;Cantatore and Timi, 2015). Indeed, the integration of parasites with other techniques may resolve fish stock structure over small geographic areas by increasing the number of spatial and temporal scales studied simultaneously leading to methods for successful management of marine fish species (Baldwin et al, 2012).…”

“…Brazil has the longest coastline in South America as well an extensive continental shelf, represented by a multiplicity of ecosystems (Miloslavich et al, Please cite this article in press as: Alarcos 2011), where fishing is an important economic and widely distributed activity along five different regions defined by their bathymetry, oceanographic structure, fauna, flora and fishery (Freire, 2003). This variety of environments along Brazilian coasts offers outstanding opportunities to use parasites as biological indicators of stock structure for diverse fish species (Cantatore and Timi, 2015). Nevertheless, the use of parasite tags remains unexplored in most regions of the Brazilian sea, despite the need to focus future actions on enhancing fisheries management to improve the regional ocean health (Elfes et al, 2014).…”

Parasite abundance and its determinants in fishes from Brazil: an eco-epidemiological approach

“…The variability in parasite abundance is important from an ecological point of view, as a potential regulator of parasite populations and as a creator of interactive spatial structures (PEDERSEN & FENTON, 2007;BELLAY et al, 2011BELLAY et al, , 2015, as well as from an epidemiological point of view, where the importance of parasite abundance in the spread of parasitic diseases is stressed (GALVANI, 2003). The best way to study patterns related to parasite abundance is by considering this quantitative parameter in the context of several host biological characteristics; therefore, databases that include hosts from the same locality to minimize geographical variations TIMI et al, 2010;HUTSON et al, 2011;CANTATORE & TIMI, 2015) are used to allow selection of a set of biotic characters common to the various species. The database used in the present study meets the requirements previously described, while simultaneously reducing the possibility of taxonomic problems related to the identification of parasites by the different groups of experts (AMARANTE et al, 2015).…”