SDG 14: Life Below Water

It is not surprising that we are interested in plastics as one of the most prominent polluting agents of the twenty-first century. We have gone from producing less than 10 million tons in the 1960s to more than 300 million in the 2010s. That plastic has had time to distribute itself, fragment and enter food chains of the oceans. Studies related to the three phenomena are now one of the main objectives of various research projects and groups around the planet. The first is understanding how fragmentation is increasing the volume of macro and microplastics, how they are dispersed at the oceanic and local level, and what their chemical characteristics are. In line with these observations and quantifications, we have to understand what influence they have on organisms and how we can reduce their concentration. For example, the displacements of macroplastics are modeled relative to their dispersion according to global and local currents, giving importance to the phenomena of fouling and fragmentation, as well as understanding how the creation of microplastics is heterogeneous according to latitude, water temperatures or seasonal conditions. One of the biggest problems is, without a doubt, the chemical, morphological and size classification of plastics, especially micro and nanoplastics. This topic is crucial, as is the standardization of the measures that we consider to classify them in one way or another. This topic has been largely discussed during the last decade, and in this chapter there are cues to understand that the consensus is very close. Other issues are still pending in the complex agenda of the understanding of these pollutants. For example, the adherence of certain types of elements such as heavy metals is a relevant issue on which much information is lacking. But it is not the only knowledge gap that we have. Dynamics in the water column and in the sediment is also a main issue, since this sediment is a sink for microplastics and nanoplastics that is continually disturbed by organisms from the meiofauna. Some of these microplastics become airborne, and their range from likely emission sources is still poorly understood. The understanding of these fluxes from the land-river to the sediments passing through the water column is one of the main challenges to solve the problems derived from the presence of such macro, micro and nano items. Marine organisms are the ones that, apparently, are the most affected by this increase in solid contamination, especially microplastics. Today they are found at any latitude, from the poles to the equator, even in places as surprising as sea ice or abyssal depths. In fact, microplastics are found in very remote places, interfering with the diet of various planktonic and benthic organisms. There are many questions to be resolved, among others, how temperature affects the retention of microplastics in organisms, or which are the most vulnerable species. And we have to understand one important issue: many of those marine organisms affected by micro and nano plastics are part of our diet. Therefore, understanding the rate of transmission in food chains in general and in our consumption in particular is a major issue. That is why we looked for solutions, such as the use of bioremediators (active suspension feeders such as sponges, sea squirts, etc.) in areas where the abundance of microplastics is especially high. Bacteria are also beginning to be used as active decomposers of microplastics, a solution that could help eliminate a large amount of this material about which we still have too many knowledge gaps regarding the health of ecosystems and our own health. The synergy of efforts to understand all these different variables is crucial. During the next decade we do have to solve this plastic problem, with coordination, standardization and the application of different tools to execute the solutions of different associated problems.

Climate change, rigorously heralded more than thirty years ago as a real threat, has become the most pressing and pernicious global problem for the entire planet. In conjunction with local impacts such as fishing, eutrophication or the invasion of alien species, to give just a few examples, the acidification of the oceans and the warming of the sea began to show its effects more than twenty years ago. These signals were ignored at the time by the governing bodies and by the economic stakeholders, who now see how we must run to repair the huge inflicted damage. Today, different processes are accelerating, and the thermodynamic machine has definitely deteriorated. We see, for example, that the intensity and magnitude of hurricanes and typhoons has increased. Most models announce more devastation of flash floods and a decomposition in the water cycle, which are factors directly affecting ecosystems all over the world. Important advances are also observed in the forecasting of impacts of atmospheric phenomena in coastal areas with more and more accurate models. Rising temperatures and acidification already affect many organisms, impacting the entire food chain. All organisms, pelagic or benthic, will be affected directly or indirectly by climate change at all depths and in all the latitudes. The impact will be non-homogeneous. In certain areas it will be more drastic than in others, and the visualization of such impacts is already ongoing. Some things may be very evident, such as coral mortalities in tropical areas or in the surface waters of the Mediterranean, while others may be less visible, such as changes in microelement availability affecting plankton productivity. In fact, primary productivity in microalgae, macroalgae and phanerogams is already beginning to feel the impact of warmer, stratified and nutrient-poor waters in many parts of the planet. Nutrients are becoming less available, temperature is rising above certain tolerance limits and water movement (turbulence) may change in certain areas favoring certain species of microplankton instead of others. All these mechanisms, together with light availability (which, in principle, is not drastically changing except for the cloudiness), affect the growth of the organisms that can photosynthesize and produce oxygen and organic matter for the rest of the trophic chain. That shift in productivity completely changes the rest of the food chain. In the Arctic or Antarctic, the problem is slightly different. Life depends on the dynamics of ice that is subject to seasonal changes. But winter solidification and summer dissolution is undergoing profound changes, causing organisms that are adapted to that rhythm of ice change to be under pressure. The change is more evident in the North Pole, but is also visible in the South pole, where the sea ice cover has also dramatically changed. In the chapter there is also a mention about the general problem of the water currents and their profound change do greenhouse gas effects. The warming of the waters and their influence on the marine currents are also already affecting the different ocean habitats. The slowdown of certain processes is causing an acceleration in the deoxygenation of the deepest areas and therefore an impact on the fragile communities of cold corals that populate large areas of our planet. Many organisms will be affected in their dispersion and their ability to colonize new areas or maintain a connection between different populations. The rapid adaptations to these new changes are apparent. Nature is on its course of restart from these new changes, but in this transitional phase the complexity and interactions that have taken thousands or millions of years to form can fade away until a new normal is consolidated.

The impacts of industrial fishing have been present in the oceans for over one hundred years, but the exponential increase all over the world and the systematic exploitation of different areas started after world war II. The phenomenon of fishing has to be understood in order to understand the changes in the oceans, and such deep transformation is essential to capture the essence of the resilience: the collapse of fish stocks, the lack of biodiversity, and the profound transformation of ecosystems due to overfishing is in part responsible for the ocean’s impacted functioning that we witness today. It now seems that the collapse of many habitats is to blame for rising acidification or temperature, but the reality is that the impact of overfishing on pelagic and benthic systems is largely responsible for the profound transformations we see today. Trawling has devastated entire ecosystems, destroying the complexity of marine forests, both those that are dominated by vegetal organisms (macroalgae and phanerogams) and those dominated by animals (corals, gorgonians, sponges, etc.). It has been possible to verify that it is not only the destruction of the structures, but the compaction of the sediment and the continuous resuspension that made possible the impoverishment of the communities and therefore of the impoverishment of the fishing stocks. Beyond these impacts, pelagic fisheries have seen profound changes in populations, which evolve to the sound of fishing pressure. The minimum size of successful reproduction (i.e. the size in which the fish is lying eggs to promote the continuity of the populations), for example, has been drastically changed in many species, making possible for populations to survive despite the immense pressure of the predator, us. In addition, these fisheries highlight the fact that many animals are trapped with nets and long lines (dolphins, turtles, birds, etc.). The solutions to these problems are sometimes difficult to apply. These large organisms are usually essential for the health status of the ecosystem and the maintenance of the biodiversity, but we are impacting them in such a way that they have become irrelevant from an ecosystem functioning point of view. The so-called by-catch of smaller organisms is another huge problem. Discards (sometimes more than 50% of fisheries) profoundly harm and transform the ecosystem, and are difficult to sell in the fishing market. Solutions have been sought for decades and this collateral damage has been denounced, but there is still a long way to go. There is also a long way to go to eliminate the high percentage (calculated in more than a quarter of the fish landings of the entire planet) of those known as illegal, unreported and unregulated fisheries. This type of mismanagement of the sea is at the heart of the active policies of many countries, but without transparency and transnational actions, it will it will be difficult to reach a good agreement to suppress or minimize them. In fisheries models, apart from direct impacts, the effects of climate change have long been implemented. As already explained in the previous chapter, rising temperatures and the effects of acidification are transforming the landscape of primary and secondary productivity. The most obvious of these changes is the fact that there will be less fishing, and therefore less production. The effect of lower productivity is already felt in several long-lasting time series, where fishing is being affected by the decrease in phytoplankton. But, in addition, there are less obvious effects. One is the substitution of species, because some are more vulnerable than others to the increase in temperature, so that in the same taxonomic and functional group those who are best adapted to the new conditions win. Another is the expansion of invasive species that directly affect the food chain, and that may feel more comfortable with the new “rules” of fisheries impact and climate change. Some animals are already undergoing these changes, such as cetaceans dying of starvation in certain areas where the synergistic effects of fishing and climate change are felt. The co-governance of fisheries, in which scientists, politicians and society work together, is essential to move forward. They are not hollow words; they are real needs in a world of an excessively accelerated change.

It is difficult to make a synthesis of the new trends in the so-called Blue Growth. This chapter opens a small window with some examples that can serve to understand a little bit the trends of some (not all) sectors that are in full expansion all over the world simultaneously, with their pros and cons. There is a need to change the rules of the game, the paradigms to which we have so far been working with. It is not a simple exercise. It needs a lot of will and a deep understanding of what are the limits and dangers of the old model in which we still live immersed. Many examples show that the actual model runs too fast and has a direct impact on natural resources and ecosystem functioning. In this framework, aquaculture is coming under specific scrutiny. We have gone from an almost negligible aquaculture figure in the ‘70s in terms of fisheries production, to almost half of the biomass extracted from the sea and continental waters from this “farming” activity. This is a considerable achievement, but it has its consequences. The impact of monocultures (salmon, shrimp, etc.) has been, in many places, equal to or worse than overfishing. Eutrophication, salinization, introduction of drugs to contain diseases, the use of wild fish to feed mariculture species or the systematic hunting of potential predators (eagles, seals, etc.) are only some of the problems associated with aquaculture nowadays. The impact on wild ecosystems such as mangroves or fjords is very relevant, and has been highlighted as one of the most important problems to be solved in coastal waters. A new vision is that of the Integrated Multitrophic Aquaculture. This is a method that is gaining strength and that may be the change we need, especially if we move from species of high energy and carbon investment (carnivores) to those species that require less energetic effort (such as bivalves, macroalgae, holothurians, etc.). To do this, one of the first things to do is a good forecast of the impact of climate change, selecting the most suitable organisms (and areas) according to the changing environmental conditions. The regional possibilities (i.e., those areas that may be suitable for a mariculture expansion) and the carrying capacity of the surrounding ecosystems according to different areas must also be taken into account if we want a significant paradigm change. Also, the inclusion of stakeholders and clear co-governance roles of these kind of infrastructures has to be understood as a tool to a successful management of the products that will be available for the local people. The Blue Growth related to the mariculture is not the only open front for the future. The use of microalgae is another type of approach to a future in which low-energy cost organisms are gradually taking center stage. The possibilities have a wide spectrum, and now these microorganisms are beginning to be applied industrially in nutraceuticals, biofuels or for the generation of interesting molecules for biomedical applications. The solutions are there, and changing the priorities and the way we apply the different discoveries to be in line with SDG14 in this Blue Growth strategy is a challenge. In fact, it is not all positive prospects in Blue Growth. There are cases in which excessive acceleration of production and inadequate management of “new generation” resources can cause stress on systems, especially in places with fragile ecosystem balances. In addition, considering the production of alternative energies such as offshore wind, or the new planning of maritime traffic, we have to deeply change our way to proceed. The Blue Growth roadmap must change the paradigm if we really want to consider it sustainable. New solutions and new perspectives in a changing world that require spatial planning and a very different model of resource management than the one we are now applying are urgently needed, considering new models of production, economy and social interaction.

The acceleration of the processes of biodiversity loss and complexity has gone too far, putting ourselves as a species in a crossroads. We now understand that it is not enough to conserve, we need to regenerate. That regeneration goes through two different paradigm changes. The first takes into account upscaling plans. That concept is based on the fact that restoration to regenerate ecosystems is on the verge, but there is a lack of a good plan to create large-scale animal and plant forest restoration programs in different areas of the oceans. The second paradigm is the participation of people, but not only as volunteers; the restoration plans need them as customers. The first paradigm is closely linked to the second. There has to be a business model that allows, in part, to pay for conservation and restoration, which, in turn, will allow for regeneration. However, we are not talking about a privatization process, as has sometimes been attempted. It is not about allowing access only to those who can afford it. Is about making people of different economic statuses and possibilities a part of the process of restoring, and giving them a real return in terms of awareness, education and enthusiasm related to the enhancement and recovery of biodiversity and complexity. People are willing to pay to maintain that complexity, that beauty, that diversity of animals and plants. Tourism can, therefore, make a difference in new conservation plans. It is not enough to expand marine protected areas, we must provide financial mechanisms so that the surveillance and infrastructure of the area we want to regenerate can be maintained. At the same time that this area is preserved, it can be replanted. Methods to quantify biodiversity, calculate the metabolism of the system and recover degraded areas with underwater gardening exist. It is demonstrated, for example, in the advances made in transplant methods for phanerogams, the environmental DNA to calculate the biodiversity of the area, and the calculations on the state of health of a coral reef. However, technology and great advances are not enough. We need to implement an inclusive policy in which local people, especially indigenous people, help in both conservation and restoration processes. They are the first that want (and need) to maintain or recover the lost habitats, but in many cases the policy makers and some stakeholders do not consider them in the equation. We must create those conditions of synergy in which the academic world, the political world and society itself (local and foreign) come together to solve the problems related to the loss of ecosystem services in the oceans.

Following the previous chapter about ecosystem conservation and restoration, we also need to strengthen the monitoring of climate change and biodiversity with the help of a plan that involves people outside the academic context. Citizen science has been shown to be a very good tool for providing useful data for scientists, if well directed. For example, the monitoring of invasive species is impossible to do from research institutes due to lack of money, tools and personnel. But well trained, even sporadic tourists can give useful information about their distribution. This is also true in the case of rare or endangered species, or in migrations or the detection of anomalies. They can also be useful in tracking marine litter, not only helping to clean beaches and seabed, but also observing the origin of that waste thanks to photos or collections that can be used to understand where the objects come from. Other observations and data collection are more complex, and require specialists to make adequate quantitative observations, but may still benefit from broad support from people who want to help in the logistical part. Once again, indigenous people are put in the spotlight, because they help to solve many problems thanks to their great local wisdom. We are realizing that many of the things we do to monitor and give keys for conservation are provided by local populations who have lived in, protected or managed the areas we want to study for hundreds of years or millennia. That is why it is important to accelerate the follow-up processes by broadening the spectrum of people who can help in these processes, professionals and non-professionals alike. However, there are limits. Specialist teams are still needed to do sampling, monitoring or experiments. The tools used by scientific research teams to make such monitoring programs have substantially advanced. The technology to keep track of the problems we have in the oceans has made a really important qualitative leap. For example, although attempts have been made to track oil spills in certain circumstances, only the collection of data by specialists can help to understand the origin of contaminants. Coastal and ocean governance needs a paradigm change. We need co-governance processes in which democratic decisions, education and awareness-raising fit together. The models in which people interact with science, problems and solutions about the oceans are more and more demanded, and the last two decades have been crucial. An authentic bottom-up process in which all these advances and the different ways of observing nature and the impacts suffered are available to non-specialists. Without that bridge, we will not be able to create the necessary conditions to reverse the process of deterioration of our oceans.