MPAs and wildlife conservation: How to localize human threats?
Modelling fishing pressure and wildlife tracking for marine spatial planning
A mosaic of threats
Nowadays, it is widely known that human activities are dramatically impacting marine species and ecosystems. From species extinction to climate change, the effects of our activities can be more or less evident where we live but, if we take a look at the global picture, the situation is worrisome.
What is happening, exactly? When looking at the marine space, a distinction between direct and indirect threats must be made. Direct stressors cause immediate damage to ecosystems and species, while indirect stressors damage the ecosystems through a concatenation of effects.
Generally, the impacts of direct threats appear after a short/medium time, hours to months, and are localized in the same area of the activities that cause them. On the other hand, the effects of indirect threats become noticeable after a more extended period of time, years in most cases, and in addition to affecting a more widespread area, they are usually displaced from the original human activities(1).
Both direct and indirect threats, however, imply long-term consequences: ecosystems are degraded, from functional to barely- or non-functional, and the structure of marine communities is altered.
Historically recognized direct threats include, for example, overfishing and habitat destruction or degradation, and the direct exploitation of organisms, mainly fishing, has the largest impact(2). Industrial fishing interests at least 55% of the ocean’s surface, and global hotspots include the northeast Atlantic, the northwest Pacific, and the upwelling areas in South America and West Africa(2). The impacts of illegal, unreported, or unregulated (IUU) fishing activities and small-scale and non-industrial fisheries (SSFs) must also be added. IUU alone, in 2011, was estimated at 33% of the global catch(3). SSFs, despite accounting for nearly half of the global catch (around 46%), are often unreported. The intense fishing activities have caused 17% of the fish stocks to be overexploited, and 52% fully exploited(4,5).
Indirect threats, among others, include climate change (and all its consequences) and land-based pollution. Climate change, as fisheries, is considered a major driver of change in ecosystems(2). Human-induced warming, in 2017, reached around +1°C (±0.2°C) compared to pre-industrial levels, with increases of 0.2°C (±0,1°C) per decade(6). It must be remembered, however, that the increase in water temperatures isn’t uniform across all oceans, with areas more susceptible to it and its consequences — the Mediterranean Sea, for example(7). Also, even if the marine systems are warming up slower than land, marine biodiversity seems more susceptible to the changing temperatures(8), and some biodiversity hotspots are localized in areas most severely affected by global warming, like in the Central-Easter Pacific Ocean and Southwestern Atlantic Ocean(9).
The impacts of direct and indirect threats are not mutually exclusive, and their cumulative impact is what determines the health of an ecosystem. From 2008 to 2013, 66% of the ocean faced an increase in cumulative human impacts(10) and, as of 2008, no area of the global ocean was unaffected by human activities, and more than 40% of the ocean, mainly the coastal areas were strongly affected(11).
Interesting is the approach of the “Anthropogenic Threat Complexes” (ATC)(12), which classifies the different combinations of drivers (climate change, habitat conversion and exploitation, pollution, and potential for alien species immigration) that impact different regions. Considering the ATC, it clearly emerges that the marine areas where most drivers overlap are, not surprisingly, also those where the human population density is the highest.
The increasing human impacts on the oceans indeed depend on land-based occurrences, including demographic pressure, socio-cultural context, economy, technological development, institutions, and governance(13).
Marine resources, like land resources, have been extensively used — directly or indirectly — to meet human needs, driven both by population dimension and lifestyle. Predictably, the growing global population and the progressively “modern” lifestyles will increase the demand for natural resources and, therefore, the pressure on the ecosystems(1).
The concept of ecosystem services (“the benefits humans obtain from nature”, MEA, 2005) well describes our dependency on nature and the irreplaceable goods and services it provides us with. They can be classified into three categories(13):
- provisioning services: products (e.g. food, raw materials)
- regulation and maintenance services: benefits (e.g. climate regulation, coastal protection)
- cultural services: non-material benefits (e.g. recreational activities)
The increasing human activities, aimed especially at exploiting provisioning services, have left many marine resources depleted or have degraded the marine systems to the point that also regulation and maintenance services have been compromised.
Approaches to threats: from local to global
Effective management of anthropogenic stressors on marine ecosystems is crucial to protect the threatened biodiversity, preventing further ecological damage and delivering goods and services to humans(1).
However, finding the balance between conservation measures and resource management is challenging. A conflict exists between achieving conservation objectives and extracting the marine resources that support billions of livelihoods globally, as their objectives are clearly opposing — reducing stressors to protect biodiversity and increasing stressors to exploit biodiversity(1).
The solution would be developing economic, social, and governance systems based on sustainable population levels and consumption, while securing the life-supporting systems and the ecosystem services they ensure(14)
Different conservation approaches are required to deal with direct and indirect threats. Direct threats can be easily addressed with localized solutions, for example, closing bounded areas from fishing or banning destructive fishing techniques (e.g. cyanide, dynamite fishing). Indirect threats, however, are more complicated to understand and, therefore, manage. They can be complicated to isolate and separate from other processes because of the displacement of causes and consequences and the local “interference” of direct threats. Also, effectively addressing indirect threats might involve long-term, large-scale changes in today’s society, first of all, the shift to more sustainable energy sources.
Local solutions, despite being more simplistic, must not be overlooked. Targeted ecosystem protection, for example through the establishment of protected areas, might decrease the cumulative impacts of threats and provide species and habitats with enough resilience to better adapt to the increasing impacts of indirect threats.
This stands true, however, if the planned conservation solutions are proven effective to mitigate local threats. Establishing MPAs, for example, doesn’t imply conservation success(15). Protected areas can be created and described in official documents, but this doesn’t necessarily lead to effective management and/or enforcement(16). Such MPAs, that live on paper only, are called “paper parks” and, even if they do not generate any conservation benefit, they count towards global and regional conservation objectives(15, 17).
A few key concepts must be considered when planning effective marine conservation solutions(1):
- The interactions between humans and the environment across multiple spatial and temporal scales
- The dynamic nature of the ecosystems and the direct and indirect interactions, changing in space and time, that shape them
- The necessity of maintaining ecological sustainability and integrity across the entire ecosystem to guarantee the delivery of ecosystem services
All these concepts provide the foundation to develop an ecosystem-based approach to conservation. This approach is defined as a “strategy for the integrated management of land, water and living resources that promotes conservation and sustainable use in an equitable way”, and is based on “the application of appropriate scientific methods, focused on levels of biological organization that encompass the essential structure, processes, functions and interactions among and between organisms and their environment”(18). Humans, and their cultural diversity, are recognized as an integral component of many ecosystems(18).
To provide ecosystem-based solutions with enough data to be effective, constant monitoring of ecosystem features and human activities is necessary.
Modelling human threats with the Wildlife Tracker
The framework “Wildlife Tracker v0.4” allows the monitoring of all the parameters needed for an effective ecosystem-based approach to conservation. Thanks to the three Earth Observation layers (oxygen concentration, chlorophyll concentration, sea surface temperature) that can be overlapped to wildlife tracks and MPAs delimitation, it is possible to have a complete picture of ecosystem dynamics and, overall, to understand how they change across time. As described in my previous blog post, these insights can be used, for example, to better plan protected areas for marine migratory species, from whale sharks to birds, by comparing the species distribution and the time effectively spent within protected areas borders in each season.
Take a look what are the plans for MPA modelling in Wildlife Tracker in my latest post:
In the next Wildlife Tracker versions, we’ll implement the possibility to see how wildlife tracks and environmental variables correlate with human impacts, in order to provide an even more complete overview of marine space and its human uses.
Currently, we are now in the process of developing a framework to add fishing data jointly with the satellite tracks and the environmental data. All these variables play a role in the MPA’s management and wildlife conservation in oceanic ecosystems.
Why fishing pressure data is important?
As noted before, fishing is one of the main direct threats ecosystems face. Solutions to mitigate fishing activities are relatively straightforward (e.g. area closure, monitoring catches, and adopting more selecting fishing tools to decrease bycatch). The model would provide actionable insights in the short run, granting delicate species and rich habitats the so much-needed protection to increase their resilience to indirect threats, while solutions to mitigate them are discussed, implemented, and on the way to being effective.
Fishing data are publicly available thanks to the efforts of Global Fishing Watch. The data would allow us to identify low-fishing and high-fish areas according to the total fishing hours recorded in the area and the specific vessel type. From previous research, it’s indeed clear that different fishing gears apply different pressure on the ecosystem in terms of damage and catches(19). Specific categories of intensity will therefore be generated for each gear type, and the region of interest will be then divided into “low-pressure” and “high-pressure” fishing areas. Additionally, following the concept of seasonality, it would be possible also to see the variation of the fishing intensity across time periods.
The addition of the fishing data in the model will provide new insights for species conservation. For example, it would be possible to closely monitor bycatch- and entanglement-sensible species, including seabirds and marine individuals, to potentially identify the areas and the season(s) in which this threat is more intense (i.e. where the larger, longer overlap between bycatch-prone fishing gear is and what the species of interest are). Similarly, by analyzing the distribution of the fishing activities, it would be possible to identify the areas where species-specific prey might decrease as a consequence of fishing activities.
Fishing data might also prompt the addition of a warning system to curb illegal activities. Similar to the water/land boundary alarm implemented for whale sharks in the context of the “Galapagos Whale Shark Project”, it might be possible to set a warning if any vessel entered the border of a no-take area nearly in real-time (three days prior to the present time, as allowed by the Global Fishing Watch Data). In no-take areas, in fact, no extractive activities, such as fishing, mining, or drilling, are allowed(20).
Moreover, a network for wildlife sightings and collision alerts can be also implemented. Vessels frequenting wildlife-rich areas in specific seasons might be prompted to report sightings and/or exercise caution to the surroundings to minimize the risk of collision with or entanglement of megafauna.
Lastly, the addition of fishing pressure to wildlife tracking and environmental variables can provide important insights aimed at more sustainable management of the marine space — according to an ecosystem-based approach.
References
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