Telmo Morato

Seamounts: Ecology, Fisheries & Conservation

1 Seamount characteristics. Paul Wessel. 2 How many seamounts are there and where are they located?. Adrian Kitchingman, Sherman Lai, Telmo Morato and Daniel Pauly. 3 A history of seamount research. Paul E. Brewin, Karen I. Stocks and Gui Menezes. 4 Physical processes and seamount productivity. Martin White, Igor Bashmachnikov, Javier Aristegui and Ana Martins. 5 Seamount plankton dynamics. Amatzia Genin and John F. Dower. 6 Midwater fish assemblages and seamounts. Filipe M. Porteiro and Tracey Sutton. 7 Seamount benthos. Sarah Samadi, Thomas Schlacher and Bertrand Richer de Forges. 8 Corals on seamounts. Alex D. Rogers, A. Baco, H. Griffiths, T. Hart and Jason M. Hall-Spencer. 9 Seamount fishes: ecology and life histories. Telmo Morato and Malcolm R. Clark. 10 Fish visitors to seamounts. Section A: Tunas and billfish at seamounts. Kim N. Holland and R. Dean Grubbs. Section B: Aggregations of large pelagic sharks above seamounts. Feodor Litvinov. 11 Seamounts and cephalopods. Malcolm Clarke. 12 Air-breathing visitors to seamounts. Section A: Marine mammals. Kristin Kaschner. Section B: Sea turtles. Marco A. Santos, Alan B. Bolten, Helen R. Martins, Brian Riewald and Karen A. Bjorndal. Section C: Importance of seamounts to seabirds. David R. Thompson. 13 Biogeography and biodiversity of seamounts. Karen I. Stocks and Paul J.B. Hart. 14 Raiding the larder: a quantitative evaluation framework and trophic signature for seamount food webs. Tony J. Pitcher and Cathy Bulman. 15 Modelling seamount ecosystems and their fisheries. Beth Fulton, Telmo Morato and Tony J. Pitcher. 16 Small-scale fishing on seamounts. Helder Marques da Silva and Mario Rui Pinho. 17 Large-scale distant-water trawl fisheries on seamounts. Malcolm R. Clark, Vladimir I. Vinnichenko, John D.M. Gordon, Georgy Z. Beck-Bulat, Nikolai N. Kukharev and Alexander F. Kakora. 18 Catches from world seamount fisheries. Reg Watson, Adrian Kitchingman and William Cheung. 19 Impacts of fisheries on seamounts. Malcolm R. Clark and J. Anthony Koslow. 20 Management and conservation of seamounts. P. Keith Probert, Sabine Christiansen, Kristina M. Gjerde, Susan Gubbay and Ricardo S. Santos. 21 The depths of ignorance: an ecosystem evaluation framework for seamount ecology, fisheries and conservation. Tony J. Pitcher, Telmo Morato, Paul J.B. Hart, Malcolm R. Clark, Nigel Haggan and Ricardo S. Santos

Seamounts are hotspots of pelagic biodiversity in the open ocean.

The identification of biodiversity hotspots and their management for conservation have been hypothesized as effective ways to protect many species. There has been a significant effort to identify and map these areas at a global scale, but the coarse resolution of most datasets masks the small-scale patterns associated with coastal habitats or seamounts. Here we used tuna longline observer data to investigate the role of seamounts in aggregating large pelagic biodiversity and to identify which pelagic species are associated with seamounts. Our analysis indicates that seamounts are hotspots of pelagic biodiversity. Higher species richness was detected in association with seamounts than with coastal or oceanic areas. Seamounts were found to have higher species diversity within 30–40 km of the summit, whereas for sets close to coastal habitat the diversity was lower and fairly constant with distance. Higher probability of capture and higher number of fish caught were detected for some shark, billfish, tuna, and other by-catch species. The study supports hypotheses that seamounts may be areas of special interest for management for marine pelagic predators.

Marine litter distribution and density in European seas, from the shelves to deep basins

Anthropogenic litter is present in all marine habitats, from beaches to the most remote points in the oceans. On the seafloor, marine litter, particularly plastic, can accumulate in high densities with deleterious consequences for its inhabitants. Yet, because of the high cost involved with sampling the seafloor, no large-scale assessment of distribution patterns was available to date. Here, we present data on litter distribution and density collected during 588 video and trawl surveys across 32 sites in European waters. We found litter to be present in the deepest areas and at locations as remote from land as the Charlie-Gibbs Fracture Zone across the Mid-Atlantic Ridge. The highest litter density occurs in submarine canyons, whilst the lowest density can be found on continental shelves and on ocean ridges. Plastic was the most prevalent litter item found on the seafloor. Litter from fishing activities (derelict fishing lines and nets) was particularly common on seamounts, banks, mounds and ocean ridges. Our results highlight the extent of the problem and the need for action to prevent increasing accumulation of litter in marine environments.

Length–weight relationships for 21 coastal fish species of the Azores, north-eastern Atlantic

Abstract Length–weight relationships were estimated for 21 coastal fish species of the Azores, namely Abudefduf luridus, Bothus podas, Chromis limbata, Coris julis, Diplodus sargus, Echiichthys vipera, Gaidropsarus guttatus, Labrus bergylta, Mullus surmuletus, Phycis phycis, Pomatomus saltator, Sarda sarda, Scorpaena maderensis, Scorpaena notata, Seriola rivoliana, Serranus atricauda, Sparisoma cretense, Sphyraena viridensis, Synodus saurus, Thalassoma pavo and Trachinotus ovatus . Significant length–weight relationships were found for all species. Sexual dimorphism did not affect the length–weight relationships, except in the cases of S. cretense and C. julis . Length–length equations for converting size measurements (standard length (SL) and fork length (FL) to total length (TL)) are also presented for all fish species.

Feeding habits, seasonal and ontogenetic diet shift of blacktail comber, Serranus atricauda (Pisces: Serranidae), from the Azores, north-eastern Atlantic

The stomach contents of 422 Serranus atricauda, sampled between June 1993 and September 1994 in the Azores (north-eastern Atlantic), were examined. Fishes and crustaceans were the main contents with gastropods, bivalves and salps uncommon. Mysids (Siriella jaltensis) and Tripterygion delaisi were the most frequent prey items followed by Capros aper, Parablennius spp., Alpheus spp. and Xantho sp. The type and quantity of food ingested changed over season. S. atricauda are generalists that can feed opportunistically on alternative prey. They are diurnal predators. Ontogenetic differences were found in the diet composition and feeding activity within the range of sizes studied. There was a significant positive relation between mean prey width and predator size.

Mapping Condor Seamount Seafloor Environment and Associated Biological Assemblages (Azores, NE Atlantic)

Publisher Summary Seamounts are among the most common topographic features in the world ocean. Depending on their particular morphological traits, they can also be referred to as banks, knolls, guyots, mounds, or hills. Condor seamount is a linear volcano located in the Azores (northeast Atlantic), 35 km in length, 2–6 km wide, and of varied seafloor morphology. A scientific observatory devoted to research on seamount ecosystem structure and functioning has been established on Condor, secured by a temporary fishing closure. Multiple projects have contributed to this observatory by targeting the seamount with snapshots and long-term deployments of moored, satellite-based, and shipborne technologies. This chapter presents a brief characterization of the seamounts seafloor environment by focusing on the multibeam bathymetry data and a series of video, oceanographic, and fishery surveys. A classification based upon the bathymetric position index is presented to characterize the landscape composition of the seamount. Habitats of conservation importance, such as coral gardens and deep-sea sponge aggregations, are documented. A qualitative zonation of the benthic assemblages based on the video surveys is presented along with dominant fish and crustacean catch data for comparable depth strata. Understanding how deep-sea habitat-building species like corals and sponges distribute at fine scales over the complex topography of individual seamounts is therefore critical information to design usage zonation schemes.

An ecosystem evaluation framework for global seamount conservation and management.

In the last twenty years, several global targets for protection of marine biodiversity have been adopted but have failed. The Convention on Biological Diversity (CBD) aims at preserving 10% of all the marine biomes by 2020. For achieving this goal, ecologically or biologically significant areas (EBSA) have to be identified in all biogeographic regions. However, the methodologies for identifying the best suitable areas are still to be agreed. Here, we propose a framework for applying the CBD criteria to locate potential ecologically or biologically significant seamount areas based on the best information currently available. The framework combines the likelihood of a seamount constituting an EBSA and its level of human impact and can be used at global, regional and local scales. This methodology allows the classification of individual seamounts into four major portfolio conservation categories which can help optimize management efforts toward the protection of the most suitable areas. The framework was tested against 1000 dummy seamounts and satisfactorily assigned seamounts to proper EBSA and threats categories. Additionally, the framework was applied to eight case study seamounts that were included in three out of four portfolio categories: areas highly likely to be identified as EBSA with high degree of threat; areas highly likely to be EBSA with low degree of threat; and areas with a low likelihood of being EBSA with high degree of threat. This framework will allow managers to identify seamount EBSAs and to prioritize their policies in terms of protecting undisturbed areas, disturbed areas for recovery of habitats and species, or both based on their management objectives. It also identifies seamount EBSAs and threats considering different ecological groups in both pelagic and benthic communities. Therefore, this framework may represent an important tool to mitigate seamount biodiversity loss and to achieve the 2020 CBD goals.

Deep-water longline fishing has reduced impact on Vulnerable Marine Ecosystems

Bottom trawl fishing threatens deep-sea ecosystems, modifying the seafloor morphology and its physical properties, with dramatic consequences on benthic communities. Therefore, the future of deep-sea fishing relies on alternative techniques that maintain the health of deep-sea ecosystems and tolerate appropriate human uses of the marine environment. In this study, we demonstrate that deep-sea bottom longline fishing has little impact on vulnerable marine ecosystems, reducing bycatch of cold-water corals and limiting additional damage to benthic communities. We found that slow-growing vulnerable species are still common in areas subject to more than 20 years of longlining activity and estimate that one deep-sea bottom trawl will have a similar impact to 296–1,719 longlines, depending on the morphological complexity of the impacted species. Given the pronounced differences in the magnitude of disturbances coupled with its selectivity and low fuel consumption, we suggest that regulated deep-sea longlining can be an alternative to deep-sea bottom trawling.

New and rare coastal fishes in the Azores islands: occasional events or tropicalization process?

Seven coastal fish species are newly reported for the remote north Atlantic archipelago of the Azores: Mediterranean sand eel Gymnammodytes cicerelus, bar jack Caranx ruber, two-banded seabream Diplodus vulgaris, bastard grunt Pomadasys incisus, unicorn leatherjacket filefish Aluterus scriptus and longspined porcupinefish Diodon holacanthus. The occurrence is also confirmed for 19 species that had been hitherto cited occasionally for the region, totalling a list of two elasmobranchs and 23 teleosts. Diplodus vulgaris, which appears to have recently colonized the islands, as well as roughtail stingray Dasyatis centroura and golden grey mullet Liza aurata, re-cited based on new records, are frequent or common coastal species in the Azores. The remaining 22 species, exceptional or rare in the region, are of tropical or subtropical affinity and find their northernmost distribution limit within the central and north-east Atlantic Ocean precisely in the Azores. This biogeographical pattern contrasts with that of the Azorean coastal fish community and suggests a tropicalization process in the region in line with previous findings of similar patterns across the north-east Atlantic Ocean and the Mediterranean Sea. These novel data from the most isolated archipelago of the North Atlantic Ocean, located in a biogeographic boundary area where colonization opportunities are reduced, reinforce the need for long-term monitoring programmes of coastal fish communities and, in particular, of indicator species groups to improve understanding of the effects of climate change on marine communities.

Tuna Longline Fishing around West and Central Pacific Seamounts

Background Seamounts have been identified as aggregating locations for pelagic biodiversity including tuna; however the topography and prevailing oceanography differ between seamounts and not all are important for tuna. Although a relatively common feature in oceanic ecosystems, little information is available that identifies those that are biologically important. Improved knowledge offers opportunities for unique management of these areas, which may advance the sustainable management of oceanic resources. In this study, we evaluate the existence of an association between seamounts and tuna longline fisheries at the ocean basin scale, identify significant seamounts for tuna in the western and central Pacific Ocean, and quantify the seamount contribution to the tuna longline catch. Methodology/Principal Findings We use data collected for the Western and Central Pacific Ocean for bigeye, yellowfin, and albacore tuna at the ocean basin scale. GLMs were applied to a coupled dataset of longline fisheries catch and effort, and seamount location information. The analyses show that seamounts may be associated with an annual longline combined catch of 35 thousand tonnes, with higher catch apparent for yellowfin, bigeye, and albacore tuna on 17%, 14%, and 14% of seamounts respectively. In contrast 14%, 18%, and 20% of seamounts had significantly lower catches for yellowfin, bigeye and albacore tuna respectively. Studying catch data in relation to seamount positions presents several challenges such as bias in location of seamounts, or lack of spatial resolution of fisheries data. Whilst we recognize these limitations the criteria used for detecting significant seamounts were conservative and the error in identification is likely to be low albeit unknown. Conclusions/Significance Seamounts throughout the study area were found to either enhance or reduce tuna catch. This indicates that management of seamounts is important Pacific-wide, but management approaches must take account of local conditions. Management of tuna and biodiversity resources in the region would benefit from considering such effects.