Cold-water corals in a changing world : potential impacts of climate change across coral life history stages

Tese de Doutoramento, Ciências do Mar (Biologia Marinha), 24 de fevereiro de 2022, Universidade dos Açores.Os corais têm uma reconhecida capacidade de construir habitats em águas rasas tropicais. No entanto muitas espécies de corais habitam águas profundas em todos os oceanos do mundo, onde formam comunidades que sustentam grande biodiversidade. Estes organismos, conhecidos como corais de águas frias ou corais de profundidade, são o foco desta dissertação. Os estudos aqui apresentados foram desenvolvidos no Arquipélago dos Açores, onde as espécies de corais de águas frias mais comuns pertencem à subclasse Octocorallia. Ao contrário dos corais escleractínios que formam recifes de coral, os octocorais criam habitats conhecidos como jardins de corais. Nos Açores, são notáveis os jardins de corais formados por densas populações de octocorais que colonizam os montes submarinos e as encostas das ilhas abaixo dos 200 m de profundidade. Os ecossistemas do mar profundo encontram-se actualmente ameaçados pelo impacto de diversas actividades humanas, tais como a pesca, a extração de petróleo e gás, a mineração do mar profundo e as alterações climáticas. Projeções com base em modelos, preveem que até o final do século, os ecossistemas do mar profundo terão que enfrentar várias alterações nas propriedades das massas de águas, incluindo aquecimento das águas, acidificação dos oceanos (AO), desoxigenação e uma diminuição no fluxo de carbono orgânico da superfície para o oceano profundo. Apesar da importância das espécies de octocorais de profundidade na região dos Açores, o nosso conhecimento relativamente às estratégias utilizadas por estes organismos em resposta a diferentes cenários de stress ambiental é extremamente limitado. A presente dissertação visa determinar os impactos potenciais das alterações climáticas nos octocorais de profundidade, focando-se em dois octocorais de águas profundas comuns nos Açores, Dentomuricea aff. meteor Grasshoff 1977 e Viminella flagellum (Johnson 1863), utilizando-os como caso de estudo. Nos primeiros capítulos da tese, foi produzida informação sobre a biologia e ecofisiologia das duas espécies-alvo durante várias fases da história de vida, incluindo a reprodução (capítulo 2), o desenvolvimento inicial (capítulo 3) e o metabolismo (capítulo 4). […].ABSTRACT: Corals are widely known for their remarkable capacity to build rich communities in tropical shallow ecosystems. However, corals can be encountered worldwide and many species thrive in deep waters where they create highly heterogenous habitats that support high biodiversity. The current thesis focuses on these organisms, known as cold-water corals or deep-sea corals. The studies presented herein were developed in the Azores Archipelago, where the most frequently encountered deep-sea corals belong to the subclass Octocorallia. Contrary to scleractinian corals which form reefs, octocorals create dense communities that are known as coral gardens. In the Azores, coral gardens are among the most frequently encountered deep-sea communities on seamounts and island slopes below 200 m of depth. Deep-sea ecosystems are experiencing increasing pressure from several anthropogenic activities, including fishing, oil and gas extraction, prospective deepsea mining and climate change. Model projections highlight that by the end of the century, deep-sea communities will have to face multiple changes, including warming, ocean acidification (OA), deoxygenation and decreased carbon input from the surface. Despite the importance of deep-sea octocorals as habitat-builders in the Azores, their potential response to climate change is currently unknown. The present dissertation aims at determining the potential impacts of climate change on deep-sea octocorals. The thesis focused on two common deep-sea octocorals in the Azores, the sea fan Dentomuricea aff. meteor Grasshoff 1977 and the whip coral Viminella flagellum (Johnson 1863), utilizing them as a case study. In the first chapters, essential knowledge on the biology and ecophysiology of the two target species was generated, focusing on major processes throughout different life history stages, including reproduction (chapter 2), early life development (chapter 3) and metabolism (chapter 4). […].Bolsa de doutoramento com a referência M3.1.a/F/047/2015 atribuída pelo Fundo Regional de Ciência e Tecnologia (FRCT) do Governo Regional dos Açores, cofinanciada pelo programa operacional regional dos Açores – Fundo Social Europeu, programas de formação avançada: doutoramentos e pós-doutoramentos, com o nº da operação FSE: ACORES-10-5369-FSE-000002. O trabalho de investigação apresentado foi co-financiado pelos projetos europeus ATLAS – “ATLAS “A Trans-Atlantic Assessment and deep-water ecosystem-based spatial management plan for Europe (H2020/project 678760) e iAtlantic “Integrated Assessment of Atlantic Marine Ecosystems in Space and Time” (H2020/project 818123) financiados pelo European Union’s Horizon 2020 research and innovation programme

Peeping through the deep: Insights to the reproductive strategies of cold water gorgonians in the Azores Archipelago

INTRODUCTION:The mean age at delivery has increased over the latest half of a century. Women of advanced maternal age have increased obstetrical risks and increased risk of chromosomal abnormalities and some other specified diagnoses in the offspring. The aim of this study was to assess the association between maternal age and overall child morbidity according to main diagnosis groups. MATERIAL AND METHODS:We conducted a national cohort study including 352 027 live firstborn singleton children. The children were born between Jan 1994 and Dec 2009 and followed to Dec 2012. Children were divided into groups according to maternal age: 15-24, 25-29, 30-34, and 35+ years. Poisson regression analyses calculated adjusted incidence rate ratios (IRR) of child morbidities according to main diagnoses groups A-Q of the International Classification of Disease 10 with adjustment for year of birth, body mass index, smoking, and mother's level of education. RESULTS:Average follow-up time was 11 years. Compared to children born to women 25-29 years, firstborn children to mothers aged 35+ had higher child morbidity in 8 of 19 main diagnosis groups and firstborn children to mothers 15-24 years had higher child morbidity in 12 of 19 main diagnosis groups. Thus, for a majority of diseases a U-shaped correlation was found, with lowest rates in women 25-29 years. CONCLUSION:Firstborn children to both older and younger mothers have higher overall morbidity as compared to children born by mothers 25-29 years

Benthic O-2 uptake by coral gardens at the Condor seamount (Azores)

Using the non-invasive aquatic eddy covariance technique, we provide the first oxygen (O-2) uptake rates from within coral gardens at the Condor seamount (Azores). To explore some of the key drivers of the benthic O-2 demand, we obtained benthic images, quantified local hydrodynamics, and estimated phototrophic biomass and deposition dynamics with a long-term moored sediment trap. The coral gardens were dominated by the octocorals Viminella flagellum and Dentomuricea aff. meteor. Daily rates of O-2 uptake within 3 targeted coral garden sites (203 to 206 m depth) ranged from 10.0 t 0.88 to 18.8 +/- 2.0 mmol m(-2) d(-1) (mean +/- SE) and were up to 10 times higher than 2 local sandy reference sites within the seamount summit area. The overall mean O-2 uptake rate for the garden (13.4 mmol m(-2) d(-1)) was twice the global mean for sedimentary habitats at comparable depths. Combined with parallel ex situ incubations, the results suggest that the octocorals might contribute just -similar to 5% of the observed O-2 uptake rates. Deposition of particulate organic matter (POM) assessed by the sediment trap accounted for less than 10% of the O-2 demand of the coral garden, implying a substantial POM supply circumventing the deployed traps. Our results expand the database for carbon turnover rates in cold-water coral habitats by including the first estimates from these largely understudied coral gardens.Peer reviewe

Biodiversity and benthic megafaunal communities inhabiting the Formigas Bank (NE Azores)

The Formigas Bank is an offshore seamount located in the easternmost part of the Azores archipelago (northeast Atlantic). It rises from abyssal depths to the surface, including a small set of islets. The bank holds multiple nature conservation designations, including a Natura 2000 Special Area of Conservation, an OSPAR Marine Protected Area, a RAMSAR site and a Nature Reserve declared under the Azores network of protected areas. The protection is based on the presence of sublittoral biotopes of high conservation interest, and importance as feeding grounds, spawning and nursery areas for many marine species, including fish, cetaceans and turtles. Although some information exists on the sublittoral communities occurring on the seamount summit (e.g., infralittoral Cystoseira and Laminaria beds, circalittoral hydrarian and sponge gardens, rich pelagic fauna), virtually no information was available on the deep-sea communities inhabiting the seamount flanks. Therefore, during the MEDWAVES cruise, the flanks of the Formigas bank have been surveyed using multibeam sonar, an ROV and oceanographic profiles, with the objective to characterise deep-sea biodiversity and megafaunal communities as well as the environment where they occur. This communication will present results from the video annotations of the ten dives made on the seamount slopes between ~500m and ~1,500 m depth. Diverse communities of sedentary suspension-feeding organisms were observed, with more than 20 cold-water coral species (mainly octocorals) being recorded, as well as many different sponge morphotypes. Dense coral garden habitats and sponge grounds were identified on several occasions, confirming the presence of vulnerable marine ecosystems (VMEs) and of ecologically or biologically significant areas (EBSAs). Differences in the abundance and composition of these habitats between the northern and southern dive transects are interpreted as reflecting substrate and geomorphological differences, as well as the potential influence of the Mediterranean Outflow Water (MOW). The new knowledge on deep-sea megafaunal communities reinforces the importance of this seamount as an area of high conservation interest

Vulnerable marine ecosystems and biological features of Gazul mud volcano (Gulf of Cádiz): A contribution towards a potential "Gulf of Cádiz" EBSA

The Gulf of Cádiz (GoC) represents an area of socioeconomic and scientific importance for oceanographic, geological and biological processes. An interesting feature of the GoC is the presence of a large amount of mud volcanoes (MVs) and diapirs that display different seepage, seabed types, oceanographic settings and biological communities. Detailed exploration of some MVs is still needed for detecting Vulnerable Marine ecosystems (VMEs) that seem to be rare in other areas of the GoC, improving the current knowledge on its biodiversity and ecological attributes. During different expeditions (MEDWAVES-ATLAS, INDEMARES-CHICA 0610 & 0412 and ISUNEPCA 0616) carried out in different years, biological samples and videos were obtained in Gazul MV (Spanish Margin of the GoC). The study of those samples and videos has revealed the presence of several ecologically important VMEs (e.g. 3 species of reef framework-forming corals, coral gardens including solitary scleractinians, gorgonians and antipatharians, as well as deep-sea sponge aggregations and chemosynthesis-related structures) and a large number of species occurring in this MV, including new records for the European margin, threatened species and non-previously described species. The combination of different environmental and anthropogenic factors allowed the present-day persistence of these VMEs in the GoC. Some of Gazul MV biological and ecological attributes fit several criteria of the Convention on Biological Diversity for EBSA description (e.g. 1,3,4,6) that, together with those of other areas of the GoC, may contribute to the future potential nomination of an EBSA in this area of the NE Atlantic

Cruise Summary Report - MEDWAVES survey. MEDiterranean out flow WAter and Vulnerable EcosystemS (MEDWAVES)

The MEDWAVES (MEDiterranean out flow WAter and Vulnerable EcosystemS) cruise targeted areas under the potential influence of the MOW within the Mediterranean and Atlantic realms. These include seamounts where Cold-water corals (CWCs) have been reported but that are still poorly known, and which may act as essential “stepping stones” connecting fauna of seamounts in the Mediterranean with those of the continental shelf of Portugal, the Azores and the Mid-Atlantic Ridge. During MEDWAVES sampling has been conducted in two of the case studies of ATLAS: Case study 7 (Gulf of Cádiz-Strait of Gibraltar-Alboran Sea) and Case study 8 (Azores). The initially targeted areas in the Atlantic were: the Gazul Mud volcano, in the Gulf of Cádiz (GoC) area, included in the case study 7, and the Atlantic seamounts Ormonde (Portuguese shelf) and Formigas (by Azores), both part of the case study 8. In the Mediterranean the targeted areas were The Guadiaro submarine canyon and the Seco de los Olivos (also known as Chella Bank) seamount. Unfortunately it was not possible to sample in Guadiaro due to time constraints originated by adverse meteorological conditions which obligate us to reduce the time at sea focusing only in 4 of the 5 initially planned areas. MEDWAVES was structured in two legs; the first leg took place from the 21st September (departure from Cádiz harbour in Spain) to the 13th October 2016 (arrival in Ponta Delgada, São Miguel, Azores, Portugal took place the 8th of October due to the meteorological conditions that obligated to conclude the first leg earlier as planned). during the Leg 1 sampling was carried out in Gazul, Ormonde and Formigas. The second leg started the 14th October (departure from Ponta Delgada) and finished the 26th October (arrival in Málaga harbour, Spain). MEDWAVES had a total of 30 effective sampling days, being 6 days not operative due to the adverse meteorological conditions experienced during the first leg which forced us to stay in Ponta Delgada from the 08th to the 13th October. During MEDWAVES the daily routine followed a similar scheme, depending of course on the weather and sea conditions. The main activity during the day, starting early in the morning (around 08:00 AM, once the night activities were finished), was the ROV deployment. Generally a single ROV dive of around 8 hours was performed, however in several occasions two dives were carried out in the same day (see General station list, Appendix II). After the ROV (and sometimes between two dives) the Box Corer and/or Van Veen Grab and/or Multicore was deployed. After these activities, during the night CTD-Rosette deployments and MB was conducted. Accordingly to this schema the scientific personnel worked in the day or in the night watch. A total of 215 sampling stations have been covered in MEDWAVES, using the following sampling gears: Multibeam echosounder, CTD-Rosette, LADCP, Box Corer, Van Veen Grab, Multicorer and a Remotely Operated Vehicle (ROV). Table 1 sumamrised the number of sampling stations conducted with each gear in each sampling zone. Additionally MB surveys have been conducted during the transits between area

Cold-water octocoral Viminella flagellum respiration rates results from an acute Cu exposure

Herein we report the respiration rates results of the cold-water coral Viminella flagellum exposed to acute Cu concentrations. In a land-based experiment, sixty nubbins of V. flagellum were distributed in six aquaria of 8 L (ten nubbins per aquarium) of each Cu solution (0 (control); 60; 150; 250; 450 and 600 μg/L) for 96 h. After this period, four nubbins from each Cu treatment, selected randomly, were incubated individually for 6 h in glass chambers filled with ca. 110 mL of 0.2 μm pre-filtered seawater, with the respective Cu dilutions (4 chambers per Cu concentration). The incubation period was set to 6 h to record changes in O2 consumption without exposing corals to oxygen levels below 80 % (air saturation, a.s.). During the incubation period, dissolved O2 (μmol/L) depletion rates were recorded every 30 min and corrected by the corresponding rates/variations in chambers without corals. Coral respiration rates were normalized to the coral surface area (cm2). Results are presented by µmol of O2 consumption per day per cm2

Collection of specimens for reproductive studies Photo-Identification guide

Disclaimer: This guide solely aims at helping with at field sampling of coral specimens. For formal specimen identification, it is highly recommended to use taxonomical guide

Counts of live embryos and planula larvae of the antipatharian coral Antipathella wollastoni exposed to different seawater temperatures

The antipatharian coral Antipathella wollastoni is commonly found in the Macaronesia (Cape Verde, Madeira, Canaries and the Azores Archipelago). In the Azores Archipelago the species forms dense populations and coral gardens on island slopes between 15-520 m water depth. Here, we present data from two experiments on the embryo and larval survival of A. wollastoni under two different seawater temperatures (21°C and 23­°C). Embryos were collected after spawning of mother colonies in aquaria. In the first experiment, we monitored the number of embryos for 24 h after spawning, while in the second experiment we monitored the number of embryos and planulae (larvae) for a total of 35 h

ATLAS Deliverable 4.1 Reproductive tissue collections for ATLAS

Brief summary on the content of this deliverable: the Deliverable includes: (1) a database on the species from which tissue collections can be made available to ATLAS partners. This can be used for reproductive histological studies to understand species reproductive and dispersal strategies and how these affect genetic connectivity (2) a bibliographic compilation on reproductive studies on cold-water coral species and sponges, as well as some general reference papers and/or book chapters