Marine Snow: An Invisible Ecosystem of Ocean

Source: freerangestock_Body of Water Surrounded by Icebergs

Introduction

From outer space, the beautiful planet Earth is often described as the “blue planet.” On the other hand, our own oceans are barely explored; we know more about the Moon and Mars. One of the most interesting and oft-overlooked phenomena occurring in the ocean is marine snow. It is a very critical process in the marine ecosystem, as it serves as a vital source of food for deep-sea organisms and impinges on the global carbon cycle.

Marine Snow

The term is used to describe various organic particles that fall from the surface of the ocean to the deep sea. Particles include dead plankton, fecal matter, viruses, bacteria, and other forms of organic debris. The term “snow” was likened due to the view that, under a porthole of a submersible, these particles appear gently falling like a snowfall.

Formation of Marine Snow

Wikimedia_Ice_sheets_in_the_global_carbon_cycle_By J L Wadham_ J R Hawkings_ L Tarasov_ L J Gregoire_ R G M Spencer_ M Gutjahr A Ridgwell & K E Kohfeld _ CC BY 4.0

The formation of marine snow is a complex process involving the interplay between a variety of biological, chemical, and physical processes. The fine cell detritus formed at the ocean’s surface through the photosynthetic activities of minute organisms known as phytoplanktons forms the organic component of this kind of snow. After phytoplankton have died, or have been consumed, their remains add to the other organic detritus raining through the water column. These are referred to as marine snow. Fecal matter may also form marine snow from large organisms like fish and whales.

As marine snow particles sink within the water column, they are colonized by bacteria and other microorganisms. These microorganisms decompose the organic material and release nutrients to be accessed by other organisms. This process of decomposition is highly critical in the ocean nutrient cycle.

Marine snow is usually considered a major food source for deep-sea organisms, with environments typically offering minimal access to solar energy and nutrients. As these marine snow particles sink further into the deep ocean, they introduce a continuous food supply of organic matter for large and small organisms such as zooplankton, benthic invertebrates, and fish.

Apart from its ecological role, marine snow is part of the vehicle of exchange in the global carbon cycle. Particles of marine snow that reach the deep ocean floor may become buried in sediments and so help to take carbon dioxide from the atmosphere and store it in the deep layer of the ocean. This has made marine snow truly a natural active carbon sink in the climatic system.

Factors that Affect Marine Snow Production

Marine snow production can be influenced by multiple factors, and these compromise

Primary productivity: The amount of phytoplankton production taking place at the ocean’s surface is the most vital determinant of marine snow production. There is generally a greater production of marine snow for higher primary productivity.
Hydrography-Ocean currents, temperature, and salinity are factors which may control, independently or in combination, the distribution and destiny of marine snow. Strong currents, for instance, transport the marine snow particles while temperature and salinity may affect the rate of decomposition.
Climate Change: The production of marine snow is expected to suffer severely due to climate change. Increases in the temperature of oceans will alter the dynamics of phytoplankton growth and decomposition rate, and shifts in the patterns of ocean circulation will impact the distribution of marine snow.

Challenges when Investigating Marine Snow

Despite its significance, marine snow continues to be a difficult subject for much of marine snow, which is elusive and working in the deep oceans. This has been studied by scientists with the use of sediment traps that are deployed into the deep ocean, where they are to collect the marine snow particles when it falls from the surface.

Submersibles: The vehicles make it feasible for scientists to research marine snow in its own environment and collect specimens for additional evaluation.
Oceanographic buoys: The buoys can be utilized to compute the density of marine snow particles of the ocean in different regions.

Future Research Directions

Although an enormous leap has taken place in comprehending marine snow, yet a myriad of things still lie undiscovered for the crucial phenomenon. A few potential avenues in which future research is likely to move ahead are:

Microorganisms’ role: How bacteria and other microorganisms participate in the formation, decomposition, and fate of marine snow is a current area of interest. Variations in climate: How climate change affects the production of marine snow and the overall global carbon cycle.
The deep-sea ecosystem: In respect to the deep-sea ecosystem, the marine snow is a vital part of it. Ongoing research is continuing to shed light on the links the marine snow shares with other deep-sea organisms.
The deep ocean is dark, cold, and much pressurized, hosting a very unique and diverse set of organisms. These are usually called extremophiles, which have adapted to survive in extreme conditions. One of the first challenges to deep-sea creatures is getting food. It represents a persistent, reliable source of organic material available to deep-sea life.

Zooplankton: Zooplankton belongs to the microscopic animals in the ocean currents and are among the major consumers of marine snow. While the marine snow falls to depths, zooplanktons may, to their subsistence, keep removing the marine snow particles from the water column to feed on. By this method, they derive important energy for their survival, and these organisms become food for the higher predator.

Examples of Benthic Invertebrates Benthic invertebrates are those living on the ocean bottom or in its immediate vicinity. They consist of a wide suite of organisms—from sea stars to sea cucumbers and worms. A good proportion of the food of benthic invertebrates comes from marine snow. When the marine snow particles reach the ocean floor, they can directly get consumed by invertebrates living their life partially or wholly in the sediments or else will be broken down by the bacteria and other microorganisms. Very recently, the nutrients are released, which can be absorbed again by bacteria and benthic invertebrates.

Although the deep ocean is less congested compared to the surface waters, many fish species have adapted to survive in the deeper parts of the ocean. In the total absence of light, some deep-sea fish like anglerfish and gulper eels develop special features in the form of appendages that help them catch prey. These fish mostly rely on the marine snow to supply the vital nutrients, either by directly consuming the snow or by feeding on zooplankton that consume the marine snow.

The Role of Bacteria in Marine Snow Degradation

Bacteria also play a big role in the breakdown of marine snow particles. The particles become colonized by bacteria and, as they sediment, bacteria break down the organic material contained in the snow to simple compounds, a process known as biodegradation. The biodegradation releases nutrients important for organisms other than the bacteria.

The factors affecting the rate of biodegradation are temperature, pressure, and availability of oxygen. With such low temperatures and limited oxygen, biodegradation will still occur but at a much slower rate. This feature may result in the burial of organic matter in the sediments presenting a reservoir: called the “sedimentary organic matter (SOM)” pool.

Marine Snow and the Global Carbon Cycle

Marine snow is an important player in the global carbon cycle because the whiskers of marine snow have the potential to be buried in sediments when they reach the deep ocean floor. In this way, the process helps withdraw carbon dioxide from the atmosphere into the deep ocean, further resulting in marine snow being termed a natural carbon sink with important controlling action on Earth’s climate.

However, a host of other factors are likely to influence the efficiency of marine snow as a carbon sink. For instance, the organic material in the marine snow particles might dissolve before reaching the deep ocean floor, in which case the bound carbon would potentially be released back to the atmosphere. Moreover, climate change-induced changes to marine snow production and the fate of marine snow in the water column could alter the significance of marine snow in the global carbon cycle.

Limitations of Deep-Sea Ecosystem Studies

There is a wide array of difficulties in studying deep ocean ecosystems. Among the extremities that characterize deep-sea environments, some should be mentioned:

For example, the tremendous pressure in the deep ocean makes it difficult to deploy and use scientific instrumentation.

Darkness: In the deep ocean, there is no direct sunshine, thus limiting the energy available to things and limiting observations from vision.
Cold Temperatures: Cold temperatures in the deep ocean may impact the rates of biological processes such as metabolism and reproduction.

Despite these challenges, scientists have made significant progress in deep-sea ecosystems. Advanced technologies, such as submersibles and remotely operated vehicles have made it possible for researchers to explore the depths of the ocean and obtain important data.

Future Research Directions

Although much was done to understand the role marine snow plays in the deep-sea ecosystem, the research on this field continues. Future research would probably work on the following:

Climate change and its impact on ecosystems: Climate change would be extremely negative for deep-sea ecosystems. It affects the temperature, ocean currents, and food supply. An internet search gives a suggestion that future studies can look at the range of implications—potential impacts of climate change on deep-sea life and the marine carbon cycle.

Microbial role: Microbes are highly active in the bulk degradation of marine snow and the recycling of nutrients in the deep ocean. Research will be done on determining the diversity and functional attributes of deep-sea micro-organism communities and their interaction with other life forms.

Discovery of new marine life environments : The deep ocean is a large and unexplored place. We will continue searching for new habitats and species, aiming to understand peculiar adaptations of the fauna inhabiting the deep sea.

In the deep-sea ecosystem, marine snow is one of the most important modalities to provide basic nutrition for a variety of animals. By understanding the role that marine snow plays within the deep ocean, scientists are able to gain valuable insights into the health of our planet and the specific ways that human activity is affecting the marine environment.

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