Aside from helping in the preservation of marine ecosystems, seabirds also provide valuable ecosystem services to humankind — making their conservation a priority
Seabirds are a "unique treasure" for the entire humankind as they provide valuable ecosystem services. Seabirds, and marine top predators in general, are conspicuous and high-profile components of marine ecosystems. The seabirds are named and well-known for the ample time they spend in and above the ocean and they also depend on the land and connect the ocean's remote terrestrial ecosystems to a larger ecological network through migration, foraging, and nesting. Their ways of life contribute to the health of island plants and wildlife, and in turn, island resources support the survival and diversity of seabird species.
Many of them are colonial seabirds, which often live in colonies and colonies may encompass several species to million individuals, while others prefer to live solitary considered as the rarest. Seabirds often prefer to live marine near shores (depositional areas) foraging and upland areas (erosional environment) for loafing and breeding. Many seabird species make remarkable migrations to nest and rear chicks on select islands. Some seabirds return to the same island year after year, a phenomenon known as "philopatry," meaning "home-loving". People around the world enjoy a famous example of philopatry in "Wisdom" the Laysan Albatross, the oldest known wild bird. Wisdom spans the open ocean to alight on Midway Atoll to nest with her mate every year. Seabirds' natural behaviours are key to functionality and biological diversity on islands and in their surrounding marine habitat. Seabirds bring important marine nutrients to islands and contribute to habitat for other species.
Unfortunately, this unique role of seabirds have been jeopardized on account of human intervention that alters a seabird's home. As a result, natural ways of seabird's life turn deadly. It is frequently observed that a seabird pair, after thousands of miles of flight, returns to a home infested with invasive predators. Invasive species such as rats and feral cats, introduced to island ecosystems by humans, put seabird colonies at risk. Many seabird species nest on the ground or in burrows, where eggs and chicks might as well be laid on a silver platter for the predatory invasive mammals. As a result, breeding cycles of seabirds fail and their populations begin to decline. This loss of seabirds is also the result of changes in land and sea use; direct exploitation of organisms; tourism and recreation, climate change; pollution, intensive farming near the coast, the transport of invasive species and, increasingly, global warming. As a result, seabird species once thriving and abundant begin to slip toward extinction.
Though seabirds play a very crucial role in providing ecological services, we practically overlook their contributions to human wellbeing as it is difficult to perceive. In this context, it is pertinent to mention that the value of seabird nutrient deposition could be up to $473.83 million annually as estimated by the researchers. Presenting this fact is the best option for drawing the attention of the general public about the importance of seabird conservation. That means monetisation of the ecological functions performed and the ecosystem services provided by seabirds can help to realize its importance in the economic and political sectors and prevent people from misinterpreting conservation efforts as a luxury.
Convincing the general public, politicians and bureaucrats in government is an enormous challenge because ecological functions and ecosystem services are critical to quantify at large scales and these are often not traded in conventional markets. These factors complicate economic valuation. Ecological functions performed by the Seabirds are key to the health of coastal and marine ecosystems and the organic fertilizer markets but their population has started to decline. Many researchers have estimated the minimum cost to replace the nutrients in the guano produced by seabirds in coastal ecosystems around the world and have also quantified ecosystem service (guano) and an ecological function (N and P deposition). Seabirds act as biological pumps between marine and terrestrial habitats through releasing high concentrations of nitrogen (N) and phosphorus (P) through their faeces, causing important environmental changes in these ecosystems. The N and P released by the non-guano-producing seabirds are expected to support ecosystem services with direct benefits to human wellbeing. Monetization of the N and P deposition of non-guano-producing seabirds has been done by multiplying the amount of N and P they excrete annually by the price of inorganic N and P (fertilisers) that are traded on the international market.
Moreover, organic manure from seabirds' excreta deposited on the land to supplement N and P practically promotes natural farming without any adverse impact on the environment particularly the marine ecosystem. Excessive use of synthetic fertilizer in agriculture and farming contains residual fertilizer that has triggered the number of dead zones, where most marine life cannot survive, resulting in the collapse of some ecosystems. The bright green colour of the water in winter is the clear evidence of the excessive delivery of nutrients from agriculture and urban centres that stimulates algal productivity, and the subsequent microbial degradation of this organic matter reduces oxygen levels, contributing towards hypoxia. In reality, low oxygen waters are also related to the acidified waters. So, Hypoxia and acidification are increasingly co-occurring in the ocean and have additive and synergistic negative effects on the growth, survival, and metamorphosis of early life stage bivalves.
In the backdrop of the quantity of synthetic fertilizers used and its impact on the environment, it may be mentioned that the N and P deposition and guano production has been reported to have a value of at least $454.4 million and $19.4 million, respectively: a total of $473.8 million per year. This is the 17 times the annual expenditure of BirdLife International in 2017 and almost three times the 2018 International Union for Conservation of Nature (IUCN) budget. The largest guano producers, Peru and Chile, extracted 27,000 tons of guano in 2018, which was sold for $12.2 million. This amount of guano represents approximately one-sixth of the guano potentially produced annually by seabirds. Therefore, conserving seabird populations is necessary to maintain their ecological functions in terrestrial and marine ecosystems.
Unfortunately, various threats faced by seabirds in both marine and terrestrial ecosystems as discussed earlier have caused higher adverse impact on the ecosystem services provided by seabirds than on the seabirds themselves. For example, climate change threatens 80 per cent of the amount of N and P deposition by seabirds but 'only' 44 per cent of seabird species. Because there are no immediate solutions to directly mitigate impacts of climate change, eradication of invasive alien species and the reduction of fishery impacts essential for seabird conservation.
The population of seabird communities must be protected to reduce the threats, to enhance the population of seabirds, and keep nature in balance for proper functions of the marine ecosystems on a sustainable basis for the future generation. Mass awareness among the public should be created how disturbance affects the population parameters of different seabird species and what is their ecological importance of balance and proper functions of the marine ecosystem. Also, how to utilize marine resources without causing disturbance to the seabird while seeking for human welfare.
A detailed strategy should be developed to address the issues, viewing guidelines, i.e., ecological importance, threats, and disturbance to the seabirds.
The writer is a former Senior Scientist, Central Pollution Control Board. Views expressed are personal