Molecular biomarkers and toxic consequences of impact by organic pollution in aquatic organisms

Organic contaminants are readily bioaccumulated by aquatic organisms. Exposure to and toxic effects of contaminants can be measured in terms of the biochemical responses of the organisms (i.e. molecular biomarkers). The hepatic biotransformation enzyme cytochrome P4501A (CYP1A) in vertebrates is specifically induced by organic contaminants such as aromatic hydrocarbons, PCBs and dioxins, and is involved in chemical carcinogenesis via catalysis of the covalent binding of organic contaminants to DNA (DNA-adducts). Hepatic CYP1A induction has been used extensively and successfully as a biomarker of organic contaminant exposure in fish. Fewer but equally encouraging studies in fish have used hepatic bulky, hydrophobic DNA-adducts as biomarkers of organic contaminant damage. Much less is known of the situation in marine invertebrates, but a CYPlA-like enzyme with limited inducibility and some potential for biomarker application is indicated. Stimulation of reactive oxygen species (ROS) production is another potential mechanism of organic contaminant-mediated DNA and other damage in aquatic organisms. A combination of antioxidant (enzymes, scavengers) and pro-oxidant (oxidised DNA bases, lipid peroxidation) measurements may have potential as a biomarker of organic contaminant exposure (particularly those chemicals which do not induce CYP1A) and/or oxidative stress, but more studies are required. Both CYP1A- and ROS-mediated toxicity are indicated to result in higher order deleterious effects, including cancer and other aspects of animal fitness

Overvåking av effekter av miljøgifter på blåskjell og torsk fra Grenlandsfjordene 1996

Denne undersøkelsen ble utført for å klarlegge om forhøyde konsentrasjoner av organiske miljøgifter i Grenlandsfjordene gir effekter på blåskjell og torsk. Effekter på blåskjell og torsk ble vurdert ved analyser av vektspotensiale (blåskjell) og påvirkning på avgiftningsenzymer (fase-1 og fase-2). Det var redusert vekstpotensiale for blåskjell fra alle tre stasjonene i Langesundsfjorden sammenlignet med blåskjell fra ytre Oslofjord (Solbergstrand). Tilsvarende ble de høyeste aktivitetene av fase-1 enzymer (benzo[a]pyren hydroksylase, BPH) funnet i blåskjell innsamlet nær Brevik, mens de laveste nivåene ble funnet i blåskjell fra Solbergstrand. Det var klare responser i begge biomarkørene hos torsk innsamlet i Frierfjorden sammenlignet med torsk innsamlet ved Brevik eller Såstein. Både fase-1 (EROD) og fase-2 (glutation S-transferase, GST) var signifikant forhøyd i torsk fra Frierfjorden sammenlignet med torsk fra Breviksfjorden eller Såstein. Det var noe forhøyde nivåer av PAH-metabolitter i galle til torsk fra Frierfjorden, men det er sannsynlig at det største bidraget til forhøyde EROD og GST aktiviteter kommer fra klorerte organiske miljøgifter

A gene to organism approach--assessing the impact of environmental pollution in eelpout (Zoarces viviparus) females and larvae

A broad biomarker approach was applied to study the effects of marine pollution along the Swedish west coast using the teleost eelpout (Zoarces viviparus) as the sentinel species. Measurements were performed on different biological levels, from the molecular to the organismal, including measurements of messenger RNA (mRNA), proteins, cellular and tissue changes, and reproductive success. Results revealed that eelpout captured in Stenungsund had significantly higher hepatic ethoxyresorufin O-deethylase activity, high levels of both cytochrome P4501A and diablo homolog mRNA, and high prevalence of dead larvae and nuclear damage in erythrocytes. Eelpout collected in Göteborg harbor displayed extensive macrovesicular steatosis, whereby the majority of hepatocytes were affected throughout the liver, which could indicate an effect on lipid metabolism. Results also indicate that eelpouts collected at polluted sites might have an affected immune system, with lower mRNA expression of genes involved in the innate immune system and a higher number of lymphocytes. Biomarker assessment also was performed on livers dissected from unborn eelpout larvae collected from the ovary of the females. No significant differences were noted, which might indicate that the larvae to some extent are protected from effects of environmental pollutants. In conclusion, usage of the selected set of biological markers, covering responses from gene to organism, has demonstrated site-specific biomarker patterns that provided a broad and comprehensive picture of the impact of environmental stressors

Kvädöfjärden, Egentliga Östersjön, 1981–2021

Inom den nationella miljöövervakningen av kust och hav bedrivs årligen sedan slutet av 1980-talet ett program för integrerad kustfiskövervakning. Programmet startades i slutet av 1980-talet och omfattar i dagsläget sju nationella referensområden; två i Bottniska viken, ett i norra Egentliga Östersjön, två i södra Egentliga Östersjön och två i Västerhavet.Syftet med programmet är att kartlägga fiskbeståndens status samt fiskens hälsotillstånd och miljögiftsbelastning för att upptäcka förändringar som indikerar storskalig påverkan av miljöhot som eutrofiering, miljögifter, klimatförändringar och andra miljöfaktorer.Detta faktablad sammanfattar resultat och bedömningar från den integrerade kustfiskövervakningen i referensområdet Kvädöfjärden i södra Östergötland. För en fördjupad presentation av resultaten se; Faktablad för Integrerad kustfisk-övervakning (Fjällbacka, Torhamn, Kvädöfjärden och Holmöarna), 2020:

Integrated biological effects and chemical contaminants approach: a case study

The OSPAR Maritime Area receives chemical pressure from approximately 140 000 hazardous substances. In the context of global change, the in situ assessment of the biological effects of chemical contaminants has achieved significant progress in standardising methodology over the past decade. An integrated approach on the biological effects of chemical contaminants has been developed for monitoring. Three methodological criteria were applied: 1) Common reference methods, 2) Quality assurance, and 3) Chemical and biological effect thresholds. Effect thresholds (EAC: Environmental Assessment Criteria) and baseline levels (BAC: Background Assessment Concentration) are unique in ecotoxicology. They were produced from monitoring data collected in the OSPAR Maritime Area. The monitoring expertise shared by OSPAR Contracting Parties over the last ten years is illustrated here by different case studies carried out under voluntary national monitoring programmes, in both coastal and offshore areas, in sites with contrasted contamination patterns, and in the short and long term. They apply a combination of biomarkers and chemical contaminants from a core list of sentinel species that were selected according to their spatial distribution (cod, herring, sole, eelpout, whiting, and saithe, as well as the broadly distributed mussel, flounder, dab, and gastropods). This original OSPAR monitoring approach forms the basis of the Marine Strategy Framework Directive’s descriptor 8 (contaminants and effects) and also contributes to the assessment of chemical exposome in the marine environment, a real challenge for the coming years.Peer reviewe