Marine Heat Waves (MHWs) are of days, weeks or even months duration in which ocean temperatures are much higher than average and they have repercussions for marine life such as corals, fish, and plankton. Whereas prior research has focused on MHWs at the ocean surface, recent investigations have shown that such an event occurs beneath depths of 200m.
Importance to study Deep Ocean MHWs
- Under-Reported Phenomena: Among the main reasons why researchers have shifted their attention towards the deep ocean MHWs is because of under-reporting of such events. Conventional approaches to observing ocean temperatures consist of measuring temperatures at the skin layer and therefore minimum information about temperatures at deeper layers. Certainly, new data on MHWs below 200 meters shall enhance the general understanding of the scope and consequences of these occurrences.
- Impact on Marine Life: The deep sea or benthic zone refers to the portion of the ocean found at or near the sea bed, in the twilight zone 200-1000 meters, are also inhabited by fish, plankton and other organisms. Such depth MHWs can have adverse impacts on the equilibrium of these ecosystems to the mutual distribution and abundance of marine species. It is also important to know when and where deep ocean MHWs occur and the impacts they have with a view of supporting the formulation of measures that will help protect and conserve marine ecosystems.
- Ocean Currents and Global Warming: These in deep-ocean are connected to ocean currents and global warming. In general, heat circulation in the upper ocean is stemmed by currents, and currents can shift heat to greater measures buoyancy, creating MHWs. Moreover, there are frequent and more intense events, such as MHWs due to global warming; thus, the study of such occurrences in the deep parts of the ocean will help evaluate the effects of these events for the future.
- Challenges of Deep Ocean Exploration: The investigation of MHWs below 200 meters poses some few difficulties. In these depths, there is minimal penetration of light through the water making it hard to get the exact temperatures. Another difficulty is a high pressure at sea-bottom and the increased degree of difficulty as the research site is in deep sea. However, technology development and data gathering techniques have offered researchers ways to identify and analyse deep ocean MHWs.
Recent Research and Findings
New research papers have improved understanding of the frequency and effects of the deep ocean MHWs. For instance, work done by Australia’s national science agency CSIRO and the Chinese Academy of Sciences showed that 80 per cent of MHWs below 100 meters are not related to events on surface. This has shown the need for the analysis of deep ocean MHWs to ensure that the information on ocean warming is well understood.
MHWs are linked to ocean currents and global warming when they are found at depths of more than 200 meters, according to Nature study. These results make it clear that there is more work to be done in understanding deep ocean MHWs in terms of their benefits and their consequences on the biological and ecological libraries of the world’s oceans for successful conservation measures to be put in place.
Implication for marine ecosystems
Deep Ocean MHWs have relatively important consequences for marine ecosystems and conservation. The knowledge of when and how these techniques happen can then allow researchers the ability to shape further approaches in order to decrease these results and preserve marine life. For instance, isolation of region that experience Deep Ocean MHWs assist in where MPAs should be created so as protect species and habitat.
Also, analysis of deep ocean MHWs can be useful for adaptation and climate change prevention strategies. In this context, investigation of the effects of MHWs on marine species offers understanding of the interaction between climate change and the ocean, equally important to propose adequate solutions.
Alarms it has raised
Ecosystem Disruption
- Impact on Marine Species: MHWs in the deep ocean are not only dangerous for the whales but also have a strong impact on the distribution and behaviour of marine living organisms. Most organisms in the deep-sea habitats are acclimatized to a given temperature range and any variation in this temperature range affects such organisms negatively and in some extreme cases causes their death. Such ecosystems can be interrupted and since most involve feeding relations and relations of predation and parasitism their disruption certainly would entail the widely ranging damage of the food chain and the loss of biological diversity.
- Coral Reef Degradation: Coral reefs mostly thrive in shallow waters, however there are some species of corals found at deeper sections. The deep ocean MHWs impacts these corals by converting it into heat stress that bleaches and decreases their own ability to cope in general. It goes without saying that coral degradation poses disproportional detriment to the reefs but also to species inhabiting coral reefs as well as the species that feed on them.
Climate Change Implications
- Alteration of Ocean Currents: Ocean currents are very important in controlling climatic conditions of the world by moving heat and nutrient all over the oceans. These deep ocean MHWs can change the features of these currents to cause changes to weather, precipitation, and even extreme weather. These changes may trigger multiple effects in habitats of organisms within aquatic and terrestrial environments.
- Carbon Storage and Release: Oxygen is moreover dissolvable in water and thus the deep ocean plays an important role as a carbon sink through the absorption of much carbon dioxide from the atmosphere. MHWs can intervene in the process, and in this case, the carbon remains that are stored on the sea bed can be released into the atmosphere.
Human Activities and Economic Impact
- Fisheries and Livelihoods: There are many communities around the world depend on deep-sea fisheries in order to survive. Vulnerable fish stocks in the deep ocean will be affected, fishing operations disrupted and communities stand to lose valuable income and food resources. It becomes important to forecast the occurrence of these heat waves whilst trying to understand the effects on fisheries for the survival of millions of people.
Key strategies that can help:
- Invest in Advanced Technologies: Equipment like AUVs and deep sea thermometer to gain real time model on temperature and current of the ocean floor. The data collected from these technologies can help understand the development and evolution of deep ocean MHWs.
- Conduct Long-term Studies: Provide sustained funding for research observing the impacts of deep ocean MHWs in the ecosystems. This includes studying the actions of marine organisms to temperature variations and evaluating the durability of the effects on species diversification as well as general health of the environment.
- Reduce Greenhouse Gas Emissions: Promote measures for decreasing the volume of emissions of greenhouse gases, which cause the intensification of MHWs impacts. This covers such areas as shift towards clean sources of energy, increasing energy efficiency and supporting sustainability.
- Promote Carbon Sequestration: Promote activities that increase the ocean's ability to store carbon, like the preservation and restoration of marine endowment including sea-grass, mangrove and salt marsh ecosystems. They are an essential nutrient for environments that serve as carbon dioxide sequestration systems.
- Expand Marine Protected Areas (MPAs): Design and scale up MPAs as a way of protecting the affected marine communities from MHWs. Sustainable uses of MPAs include offering sanctuary to marine organisms and preserve species diversities with a view of ecosystem strength.
- Implement Adaptive Management: MPA management should incorporate the principles that understand the nature of MHWs. This can be done through review of the management plans every time new scientific information is available and putting in place measures that reduce the effects of change in temperatures marine life.
- Ocean Literacy: Encourage youth to comprehend the value of the ocean and the effects that MHWs have on it through their education in schools. Explain to students various citizen science initiatives to undertake and conservation activities to support.
- Foster Global Partnerships: Promote the international cooperation since MHWs phenomena are on international level. Provide data and research findings of MHWs, and also the best practices to the other countries to formulate good strategies towards reducing the effects of MHWs.
Marine Heat Waves (MHWs)
Extended periods of warmer than average sea surface temperatures are defined as Marine heat waves (MHWs) that affect marine lives, fishing industry and coastal residents. Such event is comparable to heat-waves but they happen at the sea and result in various ecological as well as socio-economic impacts.
Types of Marine Heat Waves
- Surface MHWs: These happen at the surface of the ocean and are the most investigated kind. These are mainly caused by weather elements whose main driving forces may range from high pressure in a region that forms a dome over the ocean and prevents cold air from penetrating its base.
- Deep Ocean MHWs: These occur at waters beyond 200 meters and are associated with ocean currents and global warming. New studies have proven that deep ocean MHWs are capable of being decoupled from surface processes and have different effects on deep sea environment.
Causes of Marine Heat Waves
- Ocean Currents: In the ocean the heat is distributed by ocean currents which act as conveyor belts to move the heat from one point to the other. Fluctuations in these currents may cause the warming of some areas with warmer water thereby creating environment for MHWs.
- Air-Sea Heat Flux: This situation arises when heat is conducted from the atmosphere to the surface of the sea through high pressure systems which deny heat to escape.
- Climate Modes: Forcing elements like El Niño and La Niña have impacts on the occurrence and strength of MHWs through modifying sea temperatures ad currents.
- Global Warming: New analysis shows that climate change has caused MHWs to occur more often and be more intense due to rise in global temperatures. One can assert that ocean surface and subsurface warming are involved in the emergence of these events.
Effects of Marine Heat Waves
- Ecosystem Disruption: They might have substantial impacts on the distribution and abundance of species in a marine environment. Some organisms, such as corals, can bleach or die at some point in a high-temperature environment.
- Fisheries Impact: The changes occurring in structure and abundance of fish stocks can be caused by MHWs and affect the fish yield. It may consequently result in financial losses for fishing communities and vice versa food security.
- Coral Bleaching: Heat stress in ocean water decreases the ability of coral to carry out photosynthesis and expels the zooxanthellae from its tissues making the corals more vulnerable to diseases and death.
- Changes in Marine Biodiversity: MHWs can bring changes to the structure of the sea, some species preferring warm water temperatures while the others cannot survive in conditions like these. This change could lead to a reorganization of the functions of marine ecosystems and their components.
- Economic Consequences: The effects can result from either positive or negative MHWs activities on fisheries, tourism or coastal structures and are immensely influential to the economy of the coastal regions or stake holders.