Julia Strahl

• PhD
• PostDoc Position at Helmholtz Institute for Functional Marine Biodiversity at the University of Oldenburg (HIFMB)

The free radical nitric oxide (NO) is a powerful metabolic regulator in vertebrates and invertebrates. At cellular concentrations in the nanomolar range, and simultaneously reduced internal oxygen partial pressures (pO2), NO completely inhibits cytochrome-c-oxidase (CytOx) activity and hence mitochondrial- and whole-tissue respiration. The infaunal...

Coastal water quality and light attenuation can detrimentally affect coral health. This study investigated the effects of light limitation and reduced water quality on the physiological performance of the coral Acropora tenuis. Branches of individual colonies were collected in 2 m water depth at six inshore reefs at increasing distances from major...

Ocean warming due to climate change is predicted to profoundly affect marine ecosystems. These effects are expected to be intensified for shelf seas like the North Sea, where sea surface temperatures are predicted to increase 3 °C by 2100. Increasing seawater temperature is suggested to alter physiological performance of benthic marine invertebrate...

Ocean acidification imposes many physiological, energetic, structural and ecological challenges to stony corals. While some corals may increase autotrophy under ocean acidification, another potential mechanism to alleviate some of the adverse effects on their physiology is to increase heterotrophy. We compared the feeding rates of Galaxea fascicula...

Owing to its extraordinary lifespan and wide geographical distribution along the continental margins of the North Atlantic Ocean, the ocean quahog Arctica islandica may become an important indicator species in environmental change research. To test for applicability and ''calibrate'' the Arctica-indicator, metabolic properties of A. islandica speci...

In a warming climate, rising seawater temperatures and declining primary and secondary production will drastically affect growth and fitness of marine invertebrates in the northern Atlantic Ocean. To study the ecological performance of juvenile hydroids Hydractinia echinata we exposed them to current and predicted water temperatures which reflect t...

The brown shrimp Crangon crangon is a key component of the North Atlantic coastal food web and an important target species for the fishery economy. As the brown shrimp contains large amounts of protein and essential fatty acids, its consumption makes it a beneficial choice for humans. Commercially harvested crustaceans like C. crangon are frequentl...

Ocean warming due to climate change is predicted to profoundly affect marine ecosystems. These effects are expected to be intensified for shelf seas like the North Sea, where sea surface temperatures are predicted to increase 3 °C by 2100. Increasing seawater temperature is suggested to alter physiological performance of benthic marine invertebrate...

Little is known about the potential for acclimatization or adaptation of corals to ocean acidification and even less about the molecular mechanisms underpinning these processes. Here we examine global gene expression patterns in corals and their intracellular algal symbionts from two replicate population pairs in Papua New Guinea that have undergon...

Environmental factors can affect the rate of ageing and shape the lifespan in marine ectotherms. The mechanisms and the degree of environmental influence on aging can best be studied in species with wide ranging biogeographic distribution. One of the biomarkers of physiological ageing is the fluorescent age pigment lipofuscin, which accumulates ove...

Little is known about the potential for acclimatization or adaptation of corals to ocean acidification and even less about the molecular mechanisms underpinning these processes. Here we examine global gene expression patterns in corals and their intracellular algal symbionts from two replicate population pairs in Papua New Guinea that have undergon...

Epilithic algal communities play critical ecological roles on coral reefs, but their response to individual and interactive effects of ocean warming (OW) and ocean acidification (OA) is still largely unknown. We investigated growth, photosynthesis and calcification of early epilithic algal community assemblages exposed for 6 months to four temperat...

Net photosynthesis, dark respiration, gross photosynthesis and light, dark and net calcification of epilithic communities after six months of temperature and acidification treatment. Data are normalized to the surface area of the substrate

At two natural volcanic seeps in Papua New Guinea, the partial pressure of carbon dioxide (pCO2) in the seawater is consistent with projections for 2100. Here, the cover of massive scleractinian corals Porites spp. is twice as high at elevated compared with ambient pCO2, while that of branching corals such as Acropora millepora is greater than twof...

We investigated ecological, physiological, and skeletal characteristics of the calcifying green alga Halimeda grown at CO2 seeps (pHtotal ? 7.8) and compared them to those at control reefs with ambient CO2 conditions (pHtotal ? 8.1). Six species of Halimeda were recorded at both the high CO2 and control sites. For the two most abundant species Hali...

We investigated ecological, physiological, and skeletal characteristics of the calcifying green alga Halimeda grown at CO2 seeps (pHtotal ∼ 7.8) and compared them to those at control reefs with ambient CO2 conditions (pHtotal ∼ 8.1). Six species of Halimeda were recorded at both the high CO2 and control sites. For the two most abundant species Hali...

The bivalve Arctica islandica is extremely long lived (>400 years) and can tolerate long periods of hypoxia and anoxia. European populations differ in maximum life spans (MLSP) from 40 years in the Baltic to >400 years around Iceland. Characteristic behavior of A. islandica involves phases of metabolic rate depression (MRD) during which the animals...

General characteristics of candidate genes important for anoxia/hypoxia tolerance and general stress response identified in the A. islandica transcriptome. Given are the expected domains of the respective gene (deduced from homologene http://www.ncbi.nlm.nih.gov/sites/entrez/query.fcgi?db=homologene) and observed domains in the contig (by SMART htt...

Contigs of A. islandica which show high similarity to candidate genes involved in the ageing process and immune system functioning. Given are the expected domains of the respective gene (deduced from homologene http://www.ncbi.nlm.nih.gov/sites/entrez/query.fcgi?db=homologene) and observed domains in the contig (by SMART http://smart.embl-heidelber...

Read length (A) and contig length (B) distribution in the Arctica islandica transcriptome database. (DOC)

Quantitative expression of candidate genes for German Bight A. islandica individuals with self-induced normoxia (non-burrowing) and hypoxia/anoxia by burrowing for 3.5 days (burrowing). Oxygen concentration of the burrowing animals was not measured and oxygen conditions can only be assumed due to burrowing activity and accumulation of anaerobic end...

Details of number and length of sequences generated by 454 technology and used for the transcriptome generation before and after cleaning. (DOC)

Concentration of protein carbonyls [nmol/mg] and caspase activity [RLU/mg protein] in gill tissue of Baltic Sea A. islandica individuals exposed for 3.5 days to Normoxia, Hypoxia and Anoxia and after 1 and 6 hours re-oxygenation. Number of n per group = 6–8. (DOC)

Forward and reverse primer sequences used for semi-quantitative PCR and Sanger sequencing. (DOC)

Activities of the antioxidant enzymes catalase and glutathione peroxidase (GPx), as well as total glutathione concentrations (tGSH = GSH+GSSG) in gill tissue of Baltic Sea A. islandica individuals exposed for 3.5 days to Normoxia, Hypoxia and Anoxia and after 1 and 6 hours re-oxygenation. Data with similar symbols (*,#) are significantly different...

Environmental factors such as temperature and salinity regimes shape lifespan in marine ectotherms. We investigated whether the effect occurs through modification of metabolic reactive oxygen species (ROS)-producing processes and is thus in line with the rate of living-free radical theory of aging. We compared 6 biogeographically and climatically d...

Arctica islandica is the longest-lived non-colonial animal found so far, and reaches individual ages of 150 years in the German Bight (GB) and more than 350 years around Iceland (IC). Frequent burrowing and physiological adjustments to low tissue oxygenation in the burrowed state are proposed to lower mitochondrial reactive oxygen species (ROS) for...

A General Overview of Reactive Oxygen Species and AgingAging and Free Radicals: A General OverviewAging in Marine AnimalsRecord Holders of Extremely Short and Long Life Spans in Marine OrganismsAge Estimation in Marine OrganismsReferences

Arctica islandica reaches maximum life span potentials (MLSP) of 405 and 150 years around Iceland and Helgoland, respectively. The combined effects of a low-metabolic lifestyle, low oxidative damage, constant cellular protection and tissue maintenance, appear to slow-down the physiological aging process in A. islandica. Due to low standard metaboli...

The ocean quahog, Arctica islandica is the longest-lived non-colonial animal known to science. A maximum individual age of this bivalve of 405 years has been found in a population off the north western coast of Iceland. Conspicuously shorter maximum lifespan potentials (MLSPs) were recorded from other populations of A. islandica in European waters...

In Arctica islandica, a long lifespan is associated with low metabolic activity, and with a pronounced tolerance to low environmental oxygen. In order to study metabolic and physiological responses to low oxygen conditions vs. no oxygen in mantle, gill, adductor muscle and hemocytes of the ocean quahog, specimens from the German Bight were maintain...

Cell proliferation and apoptosis were investigated in tissues of two bivalve species, Arctica islandica from the German Bight (age of bivalves: 33–98years) and Iceland (7–148years) and Aequipecten opercularis from the English Channel (2–4years). High proliferation rates (10% nuclei dividing) and apoptosis in tissues of A. opercularis were in line w...

Owing to its extraordinary lifespan and wide geographical distribution along the continental margins of the North Atlantic Ocean, the ocean quahog Arcitca islandica may become an important indicator species in environmental change research. To test for applicability and “calibrate” the Arctica-indicator, metabolic properties of A. islandica specime...

Owing to its extraordinary lifespan and wide geographical distribution along the continental margins of the North Atlantic Ocean , the ocean quahog Arcitca islandica may become an important indicator species in environmental change research. To test for applicability and “calibrate” the ...

Environmental factors can affect the rate of ageing and shape the lifespan in marine ectotherms. The mechanisms and the degree of environmental influence on aging can best be studied in species with wide ranging biogeographic distribution. One of the biomarkers of physiological ageing is the fluorescent age pigment lipofuscin, which accumulates ove...

The ocean quahog Arctica islandica is the longest-lived of all bivalve and molluscan species on earth. Animals close to 400 years are common and reported maximum live span around Iceland is close to 400 years. High and stable antioxidant capacities are a possible strategy to slow senescence and extend lifespan and this study has investigated severa...

The ocean quahog Arctica islandica is one of the longest-living and slowest-growing marine bivalves. The oldest specimens obtained for the present study approached 200 yr. To achieve such a long lifespan, accumulation of oxidative damage markers in tissues must ideally be maintained at low levels over time, because the accumulating debris disturbs...

Rafting on floating objects is a common dispersal mechanism for many marine invertebrates. In order to identify adaptations to the rafting life style, we compared behavioural and metabolic characteristics of two isopods, the obligate rafter Idotea metallica and the facultative rafter Idotea baltica. In laboratory experiments, I. metallica showed lo...