Transcript Indirect threats.

Tomislav Skračić, MA
Undergraduate English
Course for
MARITIME MANAGERS
5th Semester
Essential reading:


T. Skračić, Waypoint – English Textbook for Maritime Students,
Faculty of Maritime Studies, Split 2010, Units 22-28
T. Trappe & G. Tullis, Intelligent Business, Longman 2005, Units
12-14

Direct threats.
There are destructive practises that seriously modify
habitats and marine systems. A dramatic example of
harmful exploitation of marine resources is the harvest of
fishes using explosives. A single blast can cause chronic
impacts over many years, decimate thousands of years of
cumulative sea bed development and can stop any
regeneration of the sea bed in the vicinity of the
explosion.

The dragging of heavy
gear such as trawls over
soft sea bed destroys the
sea life on the sea bed
and disrupts ecological
processes that are critical to
maintaining marine
productivity and diversity.

Overexploitation is another destructive practise. Our
capacity to find and harvest living marine resources has
now exceeded the natural capacity of coastal and
offshore ecosystems to restock them.

Finally, by far the most menacing direct impact that
humans have exerted on the marine ecosystem has
been the urbanisation of coastal areas.
Binhai, China – coastal urbanisation 1992-2012
Source: http://forum.santabanta.com/showthread.htm?293951-Our-ChangingEarth-Human-Expansion-and-Its-Impact
Urban agglomerations by size class and inland or coastal
location, 2011
Source: United Nations, Department of Economic and Social Affairs, Population
Division: World Urbanization Prospects, the 2011 Revision. New York 2012
Indirect threats.
Indirect impacts of commercial exploitation include
 loading of the system with discards, including fishprocessing waste and by-catch,
 habitat alteration, loss or degradation of nursery areas,
 lowered water quality in terms of chronic pollution
by fisheries operations or single pulse pollution in
catastrophic accidents.
Indirect threats.
There are myriad ways that humans indirectly impact
marine biological diversity and the ecosystems that
sustain it.
 Pollutant release,
 runoff of toxics,
 excessive fertilisation of nearshore waters from
agricultural runoff,
 release of alien species,
 changes in hydrology in river systems
... all cause dramatic changes to the ecology of nearshore
and, in some cases, offshore ecosystems.
1. Answer the following questions:
a)
b)
c)
d)
e)
Why are marine ecosystems under enormous threats?
Name some factors that contribute to continued
environmental degradation.
State a few warning signs of negative impacts on the
marine system.
What are marine resources?
What is the first sign of overexploitation of marine
resources?
1. Answer the following questions:
f)
g)
h)
Name some destructive practices that cause habitat
alteration.
What is the most menacing direct impact that humans
have exerted on the marine ecosystem?
Explain some of the indirect threats to marine
ecosystems.
2. Use the following prepositions to complete the
text: at, at, at, by, in, in, in, to, to, to.
INTRODUCTION OF ALIEN OR EXOTIC SPECIES
There are many examples of the ecological catastrophes
wreaked ________ alien species. San Francisco Bay
________ the western United States has been receiving
alien marine species ________ the rate of one every
fourteen days; many of these organisms survive, settle and
eventually displace other native species. Another example
can be found ________ northern Africa, where the opening
of the Suez Canal led ________ the spread of more than
250 species from the Red Sea ________ the Mediterranean.
2. Use the following prepositions to complete the
text: at, at, at, by, in, in, in, to, to, to.
Some of these introduced species, like the Red Sea jellyfish,
have displaced local and commercially important species,
depressed fish catches, clogged intake pipes of coastal
power plants and impacted tourism ________
Mediterranean beaches. ________ the Black Sea, ballastborne introduction of the ctenophore Cnemiopsis from the
eastern U.S. has caused the decline and population
extirpation of ________ least 28 commercially important
species of fish, and has contributed ________ the
"desertification" of a once productive and economically
important sea.
3. Discussion:
In your opinion, what is the most serious threat to
marine ecosystems in the Adriatic? What can we do about
it in terms of prevention and repression?
4. Choose some of the following structures and write
sentences of your own:
long-term (adj.), in the long term,
threatened / under threats,
address symptoms / threats,
efficient tool,
contribute to, negative impacts on,
put at risk, to date,
aimed at, committed to