Abstract:
In the age of the Anthropocene, the Ocean have typically been viewed as
a sink for our pollution. Pollution is varied, ranging from human-made
plastics and pharmaceutical compounds, to human-altered abiotic factors,
such as sediment and nutrient runoff. As the global population, wealth
and resource consumption continues to grow, so too does the amount of
pollution we produce. This presents us with a grand challenge which
requires interdisciplinary knowledge to solve. While there is sufficient
data on the human health, social economic, and environmental risks of
marine pollution, a significant lag exists when implementing strategies
to address this issue. We gathered 17 experts from the fields of social
sciences, marine science, visual arts, logistics and traditional and
first nations knowledge holders to present two futures; the
Business-as-usual, based on current trends and observations of growing
marine pollution, and a More Sustainable Future, which imagines what our
Ocean could look like if we implemented current knowledge and
technologies. We identified priority actions that governments, industry
and consumers can implement at pollution sources, vectors and sinks,
over the next decade to reduce marine pollution and steer us towards the
More Sustainable Future.
Keywords: future scenario, Sustainable Development Goals
(SDGs), pollution, ocean decade, 2030, sustainable solutions
Introduction
The Ocean has historically been a sink for pollution, leaving modern
society with significant ocean pollution legacy issues to manage
(Elliott and Elliott 2013; O’Shea et al. 2018). People continue to
pollute the Ocean at increasing rates creating further damage to marine
ecosystems. This results in detrimental impacts on livelihoods, food
security, marine navigation, wildlife and well-being, among others
(Krushelnytska 2018; Lebreton and Andrady 2019; Nichols 2014; Seitzinger
et al. 2002). As pollution presents a multitude of stressors for ocean
life, it cannot be explored in isolation (Khan et al., 2018). Thus,
global coordinated efforts are essential to manage the current and
future state of the Ocean and to minimise further damage from pollution
(Krushelnytska 2018; Macleod et al. 2016; O’Brien et al. 2019; Williams
et al. 2015). Efforts are also needed to tackle key questions, such as
how do pollutants function in different environments, and interact with
each other?
Pollution can be broadly defined as any natural or human-derived
substance or energy that is introduced into the environment by humans
and that can have a detrimental effect on living organisms and natural
environments (UNEP 1982). Pollutants, including light and sound in
addition to the more commonly recognised forms, can enter the marine
environment from a multitude of sources and transport mechanisms
(Carroll et al. 2017; Depledge et al. 2010; Longcore and Rich 2004;
Williams et al. 2015). These may include long range atmospheric movement
(Amunsen et al. 1992) and transport from inland waterways (Lebreton et
al. 2017).
Current pollutant concentrations in the marine environment are expected
to continue increasing with global population growth and product
production. For example, global plastic production increased by 13
million tonnes in a single year (PlasticsEurope 2018), with rising
oceanic plastic linked to such trends (Wilcox et al. 2020).
Pharmaceutical pollution is predicted to increase with population
growth, resulting in a greater range of chemicals entering the Ocean
through stormwater drains and rivers (Bernhardt et al. 2017; Rzymski et
al. 2017). Additionally, each year new chemical compounds are produced
whose impacts on the marine environment are untested (Landrigan et al.
2018).
Marine pollution harms organisms throughout the food-web in diverse
ways. Trace amounts of heavy metals and persistent organic pollutants
(POPs) in organisms have the capacity to cause physiological harm
(Capaldo et al. 2018; Hoffman et al. 2011; Salamat et al. 2014) and
alter behaviours (Brodin et al. 2014; Mattsson et al. 2017). Artificial
lights along coasts at night can disrupt organism navigation, predation
and vertical migration (Depledge et al. 2010). Pharmaceutical
pollutants, such as contraceptive drugs, have induced reproductive
failure and sex changes in a range of fish species (Lange et al. 2011;
Nash et al. 2004). Furthermore, some pollutants also have the capacity
to bioaccumulate, which means they may become more concentrated in
higher trophic marine species (Bustamante et al. 1998; Eagles-Smith et
al. 2009).
Pollution also poses a huge economic risk. Typically, the majority of
consequences from pollution disproportionately impact poorer nations who
have less resources to manage and remediate these impacts (Alario and
Freudenburg 2010; Beaumont et al. 2019; Golden et al. 2016; Landrigan et
al. 2018). Marine pollution can negatively impact coastal tourism (Jang
et al. 2014), waterfront real estate (Ofiara and Seneca 2006), shipping
(Moore 2018) and fisheries (Hong et al. 2017; Uhrin 2016). Contamination
of seafood poses a perceived risk to human health, but also incurs a
significant financial cost for producers and communities (Ofiara and
Seneca 2006; White et al. 2000). Additionally, current remediation
strategies for most pollutants in marine and coastal ecosystems are
costly, time consuming and may not prove viable in global contexts (Ryan
and Jewitt 1996; Smith et al. 1997; Uhrin 2016).
Reducing marine pollution is a global challenge that needs to be
addressed for the health of the Ocean and the communities and industries
it supports. The United Nations proposed and adopted 17 Sustainable
Development Goals (SDGs) designed to guide future developments and
intended to be achieved by 2030. It has flagged the reduction of marine
pollution as a key issue underpinning the achievement of SDG 14, Life
Under Water, with target 14.1 defined as “prevent and significantly
reduce marine pollution of all kinds, in particular from land-based
activities, including marine debris and nutrient pollution” by 2025
(United Nations General Assembly 2015). In the UN Decade of Ocean
Science (2021-2030), one of the six ocean outcomes relate specifically
to the reduction and identification of marine pollution (A Clean Ocean;
UN DOS SD). The task of reducing
marine pollution is daunting - the Ocean is so vast that cleaning it
seems almost impossible. However, effective management of pollution at
its source is an effective way to reduce it and protect the Ocean
(DeGeorges et al. 2010; Rochman 2016; Simmonds et al. 2014; Zhu et al.
2008). Strategies, implemented locally, nationally and globally, to
prevent, or considerably reduce pollution inputs in combination with
removing pollutants from the marine environment (Sherman and van Sebille
2016) will allow healthy ocean life and processes to continue into the
future.
To help explain how we can most effectively address pollution sources
and clean the Ocean, we depict two different future seas scenarios by
2030. The first is a business-as-usual scenario, where we continue to
adhere to current management and global trends. The second is a
technically achievable, more sustainable future that is congruent with
the SDGs, and where we actively take actions and adopt sustainable
solutions. We then explore pollution in three ‘zones’ of action; at the
source(s), along the way, and at sink, in the context of river or
estuarine systems, as water-transported pollution is commonly associated
with urban centres alongside river systems (Alongi and McKinnon 2005;
Lebreton et al. 2017; Lohmann et al. 2012; Seitzinger and Mayorga 2016).