CHAPTER ONE
1.0 INTRODUCTION
Marine debris includes any form of
manufactured or processed material discarded, disposed of or abandoned in the
marine environment. It consists of items made or used by humans that enter the
sea, whether deliberately or unintentionally, includingtransport of these
materials to the ocean by rivers, drainage, sewage systems or by wind (Galgani
et al. 2010). Once in the water, itcan
blow around, remain floating on the water surface, drift in the water column,
get entangled in algae on shallow bottoms, sink to the deeper seabed, or be
washed up onto beaches sometimes many miles away.
Theyare items and materials that
are either discarded directly (thrown or lost directly into the sea), brought
to the sea indirectly by rivers, sewage, storm water or winds, or left by
people on beaches and shores.
Marine debris is a major global threat to
biodiversity. For instance, more than six million tons of fishing gear alone is
estimated to be lost in the ocean each year (Derraik 2002). Despite this
staggering amount of marine waste, fishing gears form only a small percentage
of the total volume of debris in the ocean, not even making the list of the top
10 most common items found during coastal cleanup operations (Ocean Conservancy
2010).
The coastal areas of Nigeria have been in the
limelight in recent times due the heavy environmentalpollution resulting from
oil prospecting activities. The coastal states in Nigeria are Akwa-Ibom,
Bayelsa, Cross-River, Delta,Edo, Lagos, Ogun, Ondo and Rivers states. For
certain reasons, development, job opportunities, government attention and
commercial activities are concentrated in coastal locations than inland
locations all over the world. This phenomenon, which is best explained by
anthropologists and sociologists, is also the case in Nigeria.
It is estimated that one-quarter ofthe Nigerian
population live in the coastal zone represented by nine states (UNEP, 2007).
However, going by the 2006 census (FRN, 2007), 37.2 million representing 26.6%
of the total population live in the coastal zone.
Two-thirds of Earth’s surface is covered by ocean.
The ocean is our planet’s life support system. It drives our climate and
provides food, water and oxygen. No matter where one lives, we all depend on
the ocean in some way and we all have a responsibility to care for it.
After all, you
can’t “go green” if you don’t “live blue”.
1.1
PROBLEM
STATEMENT
Marine debris is a major global threat to
biodiversity. For instance, more than six million tons of fishing gear alone is
estimated to be lost in the ocean each year (Derraik 2002).The coastal areas of
Nigeria have been in the limelight in recent times due the heavy environmental pollution
and oil prospecting activities. However, oil pollution is not the only
environmental threat to these coastal States. Other forms of solid and liquid
wastes equally threaten the livelihood of residents of these areas. Plastics in
various forms (bottles, bags, cigarette butts and utensils) make up a category
of marine debris; they are non-biodegradable, and persist in the environment
for a long period of time. Cigarette butt, a plant based plastic also persist
in the environment for a long time.
1.2 JUSTIFICATION
OF STUDY
Discarded plastics can be re-utilized for other
economic uses without recycling. For instance, in fisheries and aquaculture,
the discarded plastic bottle corks can be useful for nitrification of
aquaculture waste water while the discarded plastic bottles can be used for
building fish farm houses amongst other uses as discussed in this work.
Beneficial uses of discarded
plastics can reduce health risks in aquatic environments. All individuals must
be sensitized to be involved in ensuring a debris free environment in order to
conserve aquatic lives, improve local economies through beaches and
recreational centers, and secure safe human health.
1.3 OBJECTIVES OF STUDY
1. To
inform about the hazardous effects of plastic marine debris
2. To
enlighten about the useful utilization of plastic marine debris
3. To
highlight the relevance of plastic marine debris to Aquaculture especially its
useful utilizations before recycling
4. To
educate on role of stake-holders in ensuring environmental safety from marine debris.