Ralf Schwamborn

Federal University of Pernambuco | UFPE · Departamento de Oceanografia

Background Unrealistic model assumptions or improper quantitative methods reduce the reliability of data-limited fisheries assessments. Here, we evaluate how traditional length-based methods perform in estimating growth and mortality parameters in comparison with unconstrained bootstrapped methods, based on a virtual population and a case study of...

Myctophids are central in ocean food webs, yet knowledge of the ecology of larval stages is sparse. We investigated if larval feeding ecology is different in continental shelf break waters compared to waters off oceanic islands in the western Tropical Atlantic. The larvae were collected through diurnal and nocturnal oblique hauls using a Bongo net...

Hello, here is the link for the complete manuscript and open-access https://authors.elsevier.com/a/1i3Dx3IHZiKd8Y

Length-at-age (LAA) and length-frequency analyses (LFA) are widely used to assess body growth in fish. The main objective of this study was to quantify and compare the uncertainty in growth parameter estimates obtained from novel bootstrapped length-at-age analysis (bootLAA) and bootstrapped length-frequency analysis (bootLFA), based on a case stud...

Zoo- and ichthyoplankton are key components of pelagic ecosystems. This study investigates zoo- and ichthyoplankton communities in seven Brazilian tropical marine environments that differ considerably in their abiotic and biological settings. The two study areas off Pará and Maranhão (Northern Brazil) present extremely wide continental shelves line...

Ongoing climate change has the potential to severely affect the tropical marine environments of Brazil. This chapter provides a brief overview of these environments with a major focus on deltas, mangrove forests, reefs, continental shelves, the zoo- and ichthyoplankton communities of pelagic ecosystems and major processes operating in the Tropical...

The connection between epipelagic and deep-sea mesopelagic realms controls a variety of ecosystem processes including oceanic carbon storage and the provision of harvestable fish stocks. So far, these two layers have been mostly addressed in isolation and the ways they connect remain poorly understood. Furthermore, both systems are affected by clim...

Stable isotope (SI) analysis is a standard tool to study marine food webs, usually based on the measurement of a few individuals from a small list of subjectively pre-defined species. The main objective of this study was to find out which species are significantly associated with the temporal variability of the SI composition of zooplankton in a tr...

This article describes six ocean datasets consistent in anomalies of biogeochemical, physical, sea wave, biological, oceanic and chemical parameters (DACS-BGC, DACS-PHY, DACS-WAVE, DACS-BIO, DACS-OCE and DACS-CHEM) in several time scales from 3-hourly to monthly frequencies, either on the sea surface, downward/upward fluxes between the ocean and th...

O presente estudo objetiva verificar se redes cônicas, de tamanho de malha diferentes, têm a mesma eficiência para amostragem de mesozooplâncton em uma plataforma continental tropical estreita, com predomínio de Água tropical. A área de estudo também tem influência da circulação da Baía de Todos os Santos, com formação de Água Costeira, além de epi...

Studies on the Copepod community structure and function under oceanographic influences and anthropic impacts was carried out in the narrowest continental shelf of Brazil. A total of 65 taxa were identified, of which 39 were Calanoida. The most abundant species was Temora turbinata (65.26%) followed by Centropages velificatus, Paracalanuspavus, Undi...

The objective of this paper is to describe and illustrate the first zoeal stage of the largest land crab of the Tropical Atlantic, Johngarthia lagostoma (Milne Edwards, 1837) (Brachyura: Gecarcinidae). A larval description of J. lagostoma was previously not available. Larvae were obtained from ovigerous females on Rocas Atoll and Fernando de Noronh...

Dendrobranchiata shrimp taxonomic composition and spatial and temporal distribution on the Amazon continental shelf (ACS) were investigated along a transect between the sources of the Amazon and Pará Rivers, encompassing an extension of ~250 km towards the continental slope. Plankton was collected with oblique trawls (200 μm mesh size), and nine ta...

Plankton organisms, biogenic particles, inorganic mineral particles, and microplastics are the four main components of particulate organic matter in aquatic ecosystems. We propose a new index, the Relative Microplastics Concentration (RMC, in %), considering that microplastics are more deleterious when food is scarce. A total of 112 plankton net sa...

Abstract Tropical reef ecosystems are generally considered to be sinks of marine zooplankton, mainly due to the predation by scleractinian corals and other planktivores. The present study aims to evaluate the zooplankton community of a coastal reef in two specific environments: the reef edge and open-water channels between patch reefs. Sampling was...

Size-based approaches are paramount tools for the study of marine food webs. Here, we investigated the relationship between zooplankton body size, stable isotope composition and trophic level (TL) along a large-scale onshore-offshore gradient in the western tropical Atlantic. Samples were obtained on the Brazilian continental shelf, slope and in oc...

Size-based approaches are paramount tools for the study of marine food webs. Here, we investigated the relationship between zooplankton body size, stable isotope composition and trophic level (TL) along a large-scale onshore-offshore gradient in the western tropical Atlantic. Samples were obtained on the Brazilian continental shelf, slope and in oc...

The western tropical Atlantic is strongly influenced by the Amazon, receiving the full discharge from the largest river basin of the world. In order to ascertain the coastal-oceanic gradient in abundance and composition of planktonic decapod communities along the Amazon River Plume (ARP) and its retroflection, 33 plankton samples were obtained alon...

Biogeographic and taxonomic knowledge on planktonic mollusks, specifically on Pterotracheoidea (also known as heteropods or sea elephants) in tropical oceans, is still incomplete. In this paper we report the first record of the heteropod Firoloida desmarestia Lesueur (1817) on waters off the Northeast Brazilian continental slope and Fernando de Nor...

Oceanographic features influence the early stages of fish to a high degree. We investigated the influence of continental shelf-slope gradient on the ichthyoplankton composition and distribution off Northeastern Brazil. Two oceanographic campaigns were performed during July-August 2010 and 2012. The samplings were performed along three transects com...

Oceanographic features influence the early stages of fish to a high degree. We investigated the influence of continental shelf-slope gradient on the ichthyoplankton composition and distribution off Northeastern Brazil. Two oceanographic campaigns were performed during July-August 2010 and 2012. The samplings were performed along three transects com...

This chapter is based on analyses of interrelations between community structure of pelagic organisms (virio-, bacterio-, protozoo-, phyto-, mesozoo-, mero- and ichthyoplankton) and abiotic factors such as spatio-temporal (rainy/dry seasons, neritic/oceanic provinces, water masses, etc.) and physico-chemical parameters (temperature, salinity, nutrie...

Species of the family Sternoptychidae (hatchetfishes) occur worldwide and play critical roles by sequestering carbon, recycling nutrients, and acting as a key trophic link between epipelagic primary consumers and higher trophic levels in marine ecosystems. Nevertheless, basic knowledge on their ecology is still lacking and their functional ecology...

In spite of the paramount ecological and socioeconomic relevance of tropical reef ecosystems, the dynamics of their meroplankton abundance remain poorly characterized. The small-scale distribution and detailed analysis of individual biomass of mesozooplankton were studied in the coastal reefs of Tamandaré (Brazil). Mesozooplankton (> 300 μm) was co...

Tagging and length-frequency analysis (LFA) are common methods to study body growth and mortality in populations of fish and invertebrates, but little has been done to assess and compare the inherent uncertainty of these methods. This study applies a new bootstrap-based approach (fishboot R package) to a case study of blue land crabs Cardisoma guan...

The zooplankton off the coast of Rio Grande do Norte, Brazil was studied during four oceanographic campaigns from July 2002 to May 2004. A Bongo net (mesh sizes of 64, 120, and 300 μm) was used for sample collections. A total of 462 zooplankton samples was studied. These samples were classified in four areas (Coastal, Inner Shelf, Shelf Break, Slop...

Isótopos estáveis são uma poderosa ferramenta analítica para estudos trofodinâmicos. Este estudo investigou fontes de matéria orgânica e a dinâmica da teia trófica planctônica em águas da Bacia de Sergipe-Alagoas. Dois cruzeiros científicos foram realizados na margem continental de Sergipe e sul de Alagoas nos períodos chuvoso (maio/junho) e seco (...

Este capítulo baseia-se em uma análise das interrelações da estrutura da comunidade de organismos pelágicos (virio-, bacterio-, protozoo-, fito-, mesozoo-, mero- e ictioplâncton) com os fatores espaçotemporais (períodos chuvoso/seco, regiões nerítica/oceânica, isóbatas etc.) e com os parâmetros físico-químicos (temperatura, salinidade, nutrientes,...

Suspended particulate matter (seston) in aquatic ecosystems contains two compartments: organisms (plankton) and particles. To know the contribution of particles to the pelagic realm is essential to understand the structure and dynamics of aquatic ecosystems. This study aims to determine the relative contribution of particles to the meso-sized sesto...

The determination of rates of body growth is the first step in many aquatic population studies and fisheries stock assessments. ELEFAN (Electronic LEngth Frequency ANalysis) is a widely used method to fit a growth curve to length-frequency distribution (LFD) data. However, up to now, it was not possible to assess its accuracy or the uncertainty inh...

Understanding the patterns of displacement and site fidelity in blue land crabs (Cardisoma guanhumi Latreille, 1825) has important implications for their conservation and management. The central objective of this study was to analyze seasonal variations in site fidelity in C. guanhumi, a species that is intensively exploited in Brazil, in spite of...

Length-based methods are the cornerstone of many population studies and stock assessments. This study tested two widely used methods: the Powell-Wetherall (P-W) plot and the Lmax approach, i.e., estimating Linf directly from Lmax. In most simulations, P-W estimates of the ratio total mortality / growth (Z/K ratio) were biased beyond acceptable limi...

The determination of rates of body growth is the first step in many aquatic population studies and fisheries stock assessments. ELEFAN (Electronic LEngth Frequency ANalysis) is a widely used method to fit a growth curve to length-frequency distribution (LFD) data. However, up to now, it was not possible to assess its accuracy or the uncertainty inh...

Tropical oceanic regions have a permanent thermocline, which prevents the mixing of surface and nutrient-rich deep waters, thus showing low productivity and planktonic biomass. Seamounts are known to disrupt the vertical stability of the water column significantly increasing the availability of nutrients in the upper layers. The Saint Peter and Sai...

At the mouth of the Amazon River, a widespread carbonate ecosystem exists below the river plume, generating a hard-bottom reef (∼9500 km²) that includes mainly large sponges but also rhodolith beds. The mesozooplankton associated with the pelagic realm over the reef formation was characterized, considering the estuarine plume and oceanic influence....

Tropical island environments are considered hotspots due to their high diversity, endemism and ecological importance. However, reports that discuss the composition and ecology of planktonic decapods in these environments are still very few. In order to ascertain the composition, abundance and spatial-temporal distribution of planktonic decapods, zo...

The first zoeal-stage larva of a possibly new species of mud shrimp Naushonia (Decapoda: Gebiidea: Laomediidae) was described from plankton samples taken off the Fernando de Noronha Archipelago, being the first occurrence at the oceanic islands of the Equatorial Atlantic. Five zoea I larvae were obtained and dissected for observation of mouthparts....

The Amazon generates the world's largest offshore river plume, which covers extensive areas of the tropical Atlantic. The data and samples in this study were obtained during the oceanographic cruise Camadas Finas III in October 2012 along the Amazon River-Ocean Continuum (AROC). The cruise occurred during boreal autumn, when the river plume reaches...

Sampling mobile zooplankton on reefs is a major challenge, mainly due to the problems faced when towing plankton nets inside complex reef mosaics. This study presents two new systems that permit precise point sampling of micro- and mesozooplankton and larvae of invertebrates and fish: the Channel Midwater Neuston Net (CMNN) and the Reef Edge Net (R...

The current biogeographic and taxonomic knowledge on decapod larvae in tropical oceans is still very incomplete, in spite of their huge ecological and socio-economic importance. The present study reports two new records for decapod larval forms in pelagic environments off oceanic islands in the western tropical Atlantic, and provides detailed dia...

The present study tested the hypothesis that endosymbionts of the zoanthid Palythoa caribaeorum show specific responses in cell density, size, and mitotic index (as proxy for cell population growth) under different environmental conditions (water depth, position within the reef and within the colony). Colony fragments were sampled at the nearshore...

This study was carried out to assess the diversity and the abundance of the reef zooplankton in the Maracajaú reefs. Samples were collected with two plankton nets (65 and 300 micrometers mesh size, each) from February to June/2000 at three stations in a transect perpendicular to coast. Plankton biomass in the 65 µm fraction varied from 45.19 mg.m -...

The biomass, biovolume and structure of the zooplankton community of the Rio Formoso estuary and Tamandaré Bay were studied during June and August 2013. This information allows a better understanding of the ecological interactions and relevant aspects of the zooplankton communities in these areas. The samples were collected using two plankton nets...

As estruturas térmicas superficial e vertical, e a circulação oceânica do sudeste do Pacífico tropical (4o S-26o S / 70o W-91o W) são aqui analisadas. Trata-se da região onde parte da Sub-Corrente do Peru-Chile se desenvolve, influenciando sobre a distribuição dos componentes bióticos e abióticos ao longo da costa do Peru, e contribuindo para a var...

Com o objetivo de obter dados dos aspectos populacionais de Cardisoma guanhumi Latreille, 1825, uma espécie de importância socioeconômica no nordeste brasileiro, e classificada pelo Ministério do Meio Ambiente como Criticamente em Perigo, foram realizadas no manguezal do CMA/ICMBio/CEPENE na ilha de Itamara-cá, Pernambuco, Brasil, coletas entre abr...

A fim de verificar a estrutura populacional de Lucifer faxoni, em diferentes estações, nas fases lunares, nos ciclos de marés e períodos do dia, realizaram-se coletas em três estações na desembocadura norte do Canal de Santa Cruz, PE - Brasil. As amostras foram coletadas durante todo dia, nas fases de sizígia e quadratura, no ciclo de marés, em ago...

Temora turbinata (Dana, 1849) é uma espécie de copépodo planctônico exótico de ampla distribuição no Nordeste brasileiro, com potencial para ser usado em testes ecotoxicológicos e como recurso de alimento vivo na aquicultura. Com o objetivo de determinar a melhor dieta para a manutenção dessa espécie em laboratório foi realizado um experimento no p...

Patrones de distribución de tamaño, sexo y relaciones alométricas del cangrejo insular Johngarthia lagostoma fueron descritos y comparados entre populaciones del Archipiélago de Fernando de Noronha (FN) y del Atol das Rocas (AR), ambos localizados en el Atlántico Tropical (Brasil). En campo, cada cangrejo fue sexado (con base en la morfología del a...

Composition changes of decapod larvae in a neotropical estuarine inlet (Catuama inlet, northeast Brazilian coast) were studied in a complete tidal cycle in August 2001. Sampling was performed at three stations at two or three depth levels that were located along a transect across the inlet. The collections were performed in 3 h intervals under a ne...

O objetivo do presente trabalho foi avaliar se as áreas de cobertura de Zoanthus sociatus (Ellis, 1768) e de macroalgas no topo da área fechada de Tamandaré apresentam associação e se juntas influenciam na variação da área de cobertura da comunidade macrobentônica séssil. As amostragens foram realizadas no topo dos recifes da área fechada de Tamand...

Tropical reefs are used for intensive tourism in various parts of the world. However, few studies have investigated the effect of regular trampling on these fragile ecosystems. The aim of this study was to assess the effect of different conservation strategies (open access, partial protection, and total long-term closure) on intertidal reef tops in...

The objective of this study was to analyze the population biology and color patterns of Cardisoma guanhumi Latreille, 1828 in a mangrove area in Natal, Rio Grande do Norte, Brazil. Crabs were collected monthly between February 2010 and January 2012 and totaled 1,837 individuals. Sex ratios were similar between males and females in the first year an...

Stable isotopes are widely used as tracers in food webs and as indicators of the trophic levels (TL) of consumers. The objectives of this study were to verify a possible ecosystem-wide increase in the relative contribution of the heavy isotope with trophic level, for carbon and nitrogen, and to analyze the relationships of C/N ratios and stable iso...

Jellyfish are often the most prominent components of plankton, with severe consequences for fisheries and tourism. However, in tropical regions, there is much uncertainty about these consequences due to the lack of basic data. Our objective was to improve the knowledge about jellyfish in the Western Atlantic, with an emphasis on understanding diver...

Island environments drastically modify the hydrodynamics of ocean currents and generate strong vertical turbulence. This leads to an upward transport of nutrient-rich waters, thus increasing the biomass of plankton in these oceanic marine environments. The objective of this study was to assess the biomass and density of the zooneuston communities i...

a b s t r a c t The objective of the present study was to analyze the distribution of manatees, dolphins and sea turtles off northea stern Brazil through aerial surveys, relating them to specific habitats and human activities, with emphasis on marine protected areas (MPAs). Surveys were conducted between January and April 2010 at 150 m altitude and...

The influence of tidal and diel changes on the exchange of Petrolisthes armatus planktonic larvae was studied at the Catuama inlet, which represents an intermediate system of marine and estuarine environments in the Northeast Brazil. To characterize the larval abundance and vertical distribution, samplings were carried out in August 2001 at neap ti...

This paper aims at describing the population ecology of the swimming crab Callinectes danae Smith, 1869 in one of the most productive estuaries of Brazil, the Santa Cruz Channel. These crabs were monthly collected from January to December/2009 at four stations along the channel, two in the upper and two in the lower estuary. A total of 2373 specime...

O presente trabalho tem por objetivo descrever a estrutura populacional do siri Callinectes danae Smith, 1869 em um dos estuários mais produtivos do Brasil, o Canal de Santa Cruz. As coletas foram realizadas mensalmente de Janeiro a Dezembro/ 2009 em quatro estações ao longo do canal, duas no estuário superior e duas no estuário inferior. Um total...

A influência dos ciclos de maré e fotoperíodo sobre o fluxo de larvas planctônicas de Petrolisthes armatus foi estudada na barra de Catuama, que representa um ambiente intermediário entre os sistemas marinho e estuarino no nordeste do Brasil. Para caracterizar a abundância e a distribuição vertical das larvas, foram feitas coletas em agosto de 2001...

Demersal zooplankton were captured with traps from a set of tropical coastal habitats (seagrass bed, coral reef, gravel, and sand bottoms) to allow comparisons among communities. Sampling was carried out during dry and rainy seasons in 2000 and 2001. Traps with and without light were placed at 18:00 and removed at 06:00 the next day for three conse...

The objective of the present study was to verify possible spatial, seasonal, and inter-annual changes in the zooplankton off Paita (northern Peru), an upwelling area located closely to the limits of cold Humboldt Current and warm Equatorial Surface Waters. Zooplankton was sampled at subsurface on 53 occasions from August 1994 to December 2004 at fo...

The zooplankton was examined in 14 commercial shrimp Litopenaeus vannamei ponds in tropical Brazil to assess their composition, determine their density, and indicate environmental quality. In each farm, two ponds and the water intake point were monitored in 2003. Sampling was made with a standard plankton net 50 micrometers mesh size. The zooplankt...

To evaluate the Maracajaú reef ecosystem (Northeastern Brazil), observations, sampling and measurements were performed monthly during spring low tides from February to June 2000, covering the transition from dry to rainy season. In this area, there is an extensive (approximately 10 km x 4 km), but to date poorly investigated, offshore coral reef fo...