MAE: Critical stressors

Many factors can be considered critical stressors. Climate change, and associated sea surface temperature rise and ocean acidification, for instance. However, there are also many local stressors affecting the health marine organisms. Local addition of CO2 via GASDRIVE powered ships, oil spills, and heavy metals are just to name but a few. Marine Animal Ecology studies the effect of these stressors on marine life through various experiments.

GASDRIVE

The aim of GASDRIVE is to develop sustainable, energy efficient ships with limited expulsion of carbon dioxide. The goal is to achieve a 50% reduced fuel demand compared to traditional ships. In order to realize this, the ships will be fueled by liquid natural gas (LNG) and exhaust gas consisting mostly of CO2 as underwater bubbles along the ship's hull to reduce drag. This all sounds amazing, but attention should also be paid to exactly this local addition of CO2. Together with Wageningen Marine Research, Marine Animal Ecology focusses on the risk impact for local marine ecosystems. Projects include:

Plates covered with benthic colonizers to be tested in mesocosms. Photo: Dr. E. Foekema.
Plates covered with benthic colonizers to be tested in mesocosms. Photo: Dr. E. Foekema.

Environmental quality and seafood safety in the Yangtze estuary

The Yangtze delta estuary is heavily polluted due to industrial development. A current project is studying a diversity of toxic compounds and their effects on benthic ecosystem services including seafood safety, and whole ecosystem stability. A risk assessment will be performed.

Risk assessment of toxic compounds such as heavy metals and POPs in the Yangtze delta region. Credit: P. Bao.
Risk assessment of toxic compounds such as heavy metals and POPs in the Yangtze delta region. Credit: P. Bao.

Oil spills

Even though there are many developments in the 'clean energy' sector, the demand for oil still remains present and is increasing. The demand on the one hand leads to exploitation of new oil sources such as those present in the Arctic. This will lead to the seepage of oil into the Arctic marine environment. However, most research on effects of toxic oil in marine systems has focussed on temperate environments. A project aims to fill the knowledge gap about acute effects of oil on Arctic marine systems.

Sampling in the Arctic region. Photo: Dr. M. van den Heuvel-Greve.
Sampling in the Arctic region. Photo: Dr. M. van den Heuvel-Greve.

Furthermore, transport of oil may not always goes as planned, as for instance happened in 2010 during the largest oil spill in US history: the Deepwater Horizon oil spill. To clean up the estimated 700 million liters of oil in the Gulf of Mexico 7 million liters of dispersants were used. The Center for Integrated Modeling and Analysis of Gulf Ecosystems consortium (C-IMAGE) is researching processes, mechanisms and environmental consequences of marine oil spills. A project of Marine Animal Ecology focusses on the role of marine snow in oil spills and associated Marine Oil Snow Sedimentation and Flocculent Accumulation (MOSSFA).

Deepwater Horizon oil spill in the Gulf of Mexico.
Deepwater Horizon oil spill in the Gulf of Mexico.

Finally, BestBioSurf is focussing on developing a eco-friendly surfactant to clean up oil spills without the negative side effect of the creation of MOSSFA events.

EPS formation in the Gulf of Mexico after the Deepwater Horizon oil spill, and in a test tube in the MAE laboratory. Photos: A. Diercks and Dr. E. Foekema.
EPS formation in the Gulf of Mexico after the Deepwater Horizon oil spill, and in a test tube in the MAE laboratory. Photos: A. Diercks and Dr. E. Foekema.

Effects of electromagnetic fields

A current project is looking at electromagnetic fields arising from offshore power cables as a critical stressor. Wind energy from the sea needs to be brought to shore through these cables. However, sharks and rays are examples of marine organisms that use electromagnetic fields for prey capture. It is unknown if power cables will affect the behavior and/or migration patterns of these elasmobranchs, which is exactly what the project will focus on.

ElasmoPower project. Credit: A. Hermans.
ElasmoPower project. Credit: A. Hermans.

Genotoxic potency

In order to manage water quality, effective methods need to be developed to adequately assess pollutants. A current project is working on developing a method to concentrate and chemically analyze low concentrations of hydrophilic contaminants. The aim is to make visible these often unseen, unmeasured and unknown contaminants that can still have very severe effects such as genotoxicity and endocrine disruption. A bioassay will be developed to quantify the potency of hydrophilic compounds termed the 'HyGenChip'.

Icon of HyGenChip project. Credit: A. Karengera.
Icon of HyGenChip project. Credit: A. Karengera.

Techniques used & Implications

To study critical stressors, Marine Animal Ecology uses a combination field, mesocosm and lab experiments. If we understand the effects of various pollutants better, we can manage them to reduce exposure. This will allow us to conserve ecosystems better and increase climate resilience.