Is tourism affecting polychaete assemblages associated with rhodolith beds in Northeastern Brazil?

Abstract

ABSTRACT. Introduction: Rhodoliths are biogenic structures distributed worldwide, formed by several types of calcareous algae. They may host a great diversity of marine invertebrates, among which polychaetes are conspicuous and diversified representatives. Rhodolith beds are notwithstanding vulnerable to several human activities (e.g. exploitation of commercial species associated with rhodoliths, petroleum exploration, fishing activities, effluent discharges, and tourism), which may compromise that diversity. Tourism is presently increasing its impact on rhodolith beds. Global warming and ocean acidification are also determinant factors in faunal change. Objective: to analyse the polychaete assemblages associated with rhodolith beds subject to different intensities of touristic pressure at Seixas Beach (NE Brazil), where tourism is gradually increasing over time. Methods: Effects were evaluated at two depths, 1.5 m and 4.0 m. Sampling was done every two months during 2015, encompassing the two marked seasons of the year in the region (rainy and dry). Quadrats of 15 x 15 cm were placed in each depth during sampling. All rhodoliths present within the quadrat were collected (usually four to five rhodoliths). Our hypothesis was that the deeper depth and the samples from the dry season months would be increasingly subject to the impact of tourism. Results: Overall, 49 species were found (from 21 different families), and a total of 733 individuals were collected. The most abundant species was Eunice wasinensis (280 individuals, 38.2% of total abundance). The species Eurythoe complanata, Eunice biannulata, E. wasinensis, Lysidice ninetta, Oxydromus pugettensis and Ceratonereis (Ceratonereis) singularis appeared in all months. The study detected a tendency for higher diversity to occur at the depth of 1.5 m for all indices, but only the Shannon-Wiener values were significantly higher there (p < 0.05). No clear differences were found regarding months or season. Conclusions: These results suggest that a higher potential pressure due to tourism may occur at 4.0 m due to more intense craft shipping activities (traffic of catamaran boats transporting tourists to and from the reefs) in that area.

The Punta de la Mona Rhodolith Bed: Shallow-Water Mediterranean Rhodoliths (Almuñecar, Granada, Southern Spain)

“…In maërl communities of shallow European Atlantic beds, Peña and Bárbara (2010) obtained similar H′ indexes (1.98-2.96), but for all associated species, not just for coralline algae. Likewise, our results are similar to those obtained by Costa et al (2019) in a tropical environment and at depths shallower than our study. The coralline algae diversity, as the proportional distribution of species in the ecosystem, is remarkable due to its high values, and the Punta de la Mona can be considered as a "nano-hotspot" (in the sense of Cañadas et al, 2014 for terrestrial regions) of rhodolith biodiversity in the biogeographical context of the Alborán Sea.…”

Marine invertebrates associated with rhodoliths/maërl beds from northeast Brazil (State of Paraíba)

“…These events modify the physical-chemical parameters of the water, which may compromise the rhodolith banks and, hence, the associated biota ( Horta et al 2015 ), affecting survival and levels of calcification and photosynthesis, causing the bleaching phenomenon ( Martin et al 2013 , Martin and Gattuso 2009 ). Therefore, the conservation of these algae (and habitats) is critical, because this action may guarantee the habitat conservation of a large diversity of marine fauna ( Costa et al 2019 , OSPAR-Commission 2010 ), using, for example, tools for promoting environmental awareness and ocean literacy ( Costa et al 2021 ).…”

Polychaetes (Annelida) associated with macroalgae and coral reefs at a protected tropical island from the Atlantic coast

“…The species Eurythoe complanata (Pallas, 1766), B. obscura, M. stylobranchiata, Pherusa scutigera (Ehlers, 1887), C. singularis, N. riisei, P. gallapagensis, P. schmardaei, B. nigromaculatum andT. plagiostoma are associated with rhodolith beds (Corallinales, Rhodophyta), possible using these biogenic structures as a nursery (Costa et al 2019). The species from families Amphinomidae (E. complanata), Phyllodocidae (Phyllodoce spp.…”

“…Further studies in the region are needed for a better understanding of polychaete fauna and the increasing impact of human activities (pollution and tourism), e.g. a study that evaluated the touristic impact in Paraíba state coast (Costa et al 2019). Besides, local governments need to develop conservation strategies and act more effectively to impede the capture of threatened invertebrates.…”