|
Review of the
Proposal that Follows By Reef Ball: There are a number of accepted artificial reef concepts that would be
helpful to further refine this proposal. For example, Artificial Reefs can be classified in a continuum from fish attraction to fish
production (i.e. a F.A.D. or Kite could be classified as fish attractor, a
standard Reef Ball™ |
“Feasibility Study of Marine
Artificial Reefs for Rehabilitation of Demersal Fishes in the Persian Gulf,
Iran”
Iranian
Fisheries Company
#250, Fatemi
Ave., Tehran, Iran
Cellphone:
0911-717-5578
Fax:
+98-21-694 13 67
Email: h_azhdari@yahoo.com
Feasibility
Study of Marine Artificial Reefs for Rehabilitation of Demersal Fishes in the
Persian Gulf, Iran”
Nowadays
destruction of marine environments caused by human and natural reasons such as
overfishing and pollution etc. have been made fishing activities to be
unsuccessful. The main reason for this is that the stocks have decreased
sharply, and catch trend is declining fast. Many countries have started
establishment of such artificial reefs. Scientists believe that, artificial
reefs have positive effects on stocks and sea production.
Persian Gulf
is not an exception to this global problem. The most recent information shows
that catch quantity has decreased and stocks has damaged. There are different
ways to reduce pressure on stock i.e. limitation of catch, modifying fishing
gears, artificial propagation and releasing aquatics such as fishes, shrimps
etc. One of methods for solving this problem is creation of artificial reefs.
Now, the fisheries cooperatives,
associations, fishers, who are interested in artificial reefs have become more
active in producing such structures. Establishment of artificial reefs increases productivity throughout the sea
PGI (Persian Gulf-Iran).
1.2.
Statement of proposal
This
project aims to address the problem of fisheries recourse reduction through
creation of artificial reefs, study the biological and ecological aspects of
restocked aquatics and investigate the effects of artificial reefs on the
natural environment. The artificial reefs increase productivity and possibility
of the development of aquatic population throughout the sea PGI (Persian
Gulf-Iran).
The
artificial reefs will be constructed from:
(a)
The designed
materials such as Reef Balls(tm) and
fish havens in different sizes and holes on them, which they are arithmetically
designed in terms of hydrographical aspects, to have less resistance against
sea currents and waves. Usually they are made of concrete (Fig. 1-2)
(b)
Out used
materials, e.g. broken concrete, columns, bridges, big pipes, big pieces of
metals, old ships, old airplanes, and old machines. To take the environmental
and pollution problems into consideration, their weights should be between 0.5
kg –10 tons.
(c)
Each of
stations include 50 reefballs, 5o fish haven a hundred out use material. The
table number 2 shows the kid, weight, size and number of artificial reefs.
After establishing
artificial reefs in the sea, aquatic animals will start to live around and
inside them. These include different fishes especially demersal species such as
Grouper, Snapper, as well as mollusks, eel, algae, crustaceans, echinoderms,
corals, sponges, and other aquatics.
After a period, they will look like a part
of natural reefs and will support production in the sea. In addition, the
artificial reefs can be used for restocking and a site for sport diving as
well. They also can be used as sites for training of students of marine biology
and consider as an attractive place for the people interested in sea life.
Decreased catching
in the sea has resulted in decreasing of fishing income and unemployment for
anglers and fishermen. On the other hand value of aquatic proteins and day to
day increasing demand for them, are the major reasons indicating the
significance and importance of creating artificial reefs and attracts attention
for using these structures for rehabilitation.
The results of this project can help enhance marine stocks, which
in turn help in increasing occupation and income of fishermen. On the other
hand it can increase recourses of some species which have been reduced
significantly.
1.4.1.
Feasibility study on establishment of artificial reefs in the Persian Gulf.
1.4.2.
Investigation of production increases caused by established artificial reefs in
the Persian Gulf.
1.4.3.
Evaluation of efficiency of established artificial reefs in terms of occupation
and income in fisheries sectors in the Persian Gulf.
1.4.4.
Protection of critically decreased populations of aquatic animals.
1.4.5.
Resource enhancement of commercially important marine species.
2.
Literature review
Human has built artificial reefs
in sea using construction materials,
trunks, stones, big potteries,
centuries before and they have caught more fishes. Since 1950's some countries
such as Japan , Malaysia, China, America, England and many costal countries
have started research projects on artificial reefs. Now it is believed that
these reefs can increase resources and production. Coastal countries in the
Persian Gulf such as Kuwait, Saudi Arabia, U A E, Oman and Qatar have also
started creation of artificial reefs and they have developed artificial reefs
in vast areas.
In Iran, from centuries ago
fishermen specially Bushehr's people were carrying out such activities such as
placing and throwing stones, trunks and the big potteries in costal waters
resulting in increased catch. They believed that these reefs are useful for
restocking fishes. Pearl oyster fishers in Bandar-e-Lengeh create artificial
reefs using tree branches to collect oyster spats. After a few weeks they shake
the branches for releasing the larva and placing them on seafloor.
Rostamian (1995) has undertaken a
study on the possibility of artificial reef establishment in the Iranian waters
of the Persian Gulf indicating positive increment in fish stocks. Although in this study, lack of facilities
and using standard structures as well as lack of baseline information on pre
and post deployment of artificial reefs have not provided a reasonable view in
this respect.
In Asia, America
and Europe many coastal countries such as Japan, China, Malaysia, Australia,
India, Italy, France, Britain, Spain, Portugal, Norway, Canada, Brazil, Peru,
USA many research projects have been undertaken to investigate:
(1) The effect of artificial reefs in primary and secondary
production.
(2) Using old and out used tiers for
creating artificial reefs in marine
environment.
(3)
Effects of marine currents and waves on artificial reefs and evaluate the
effects of (hydrograph logy) hydrology on them.
(4) Biology of aquatic systems living on artificial reefs.
(5) Possibility of coral settlement on artificial reefs.
(6) Using oil industrial items such as platforms in creating the
artificial reefs.
(7) Using unpolluted materials and constructions as marine
artificial reefs.
(8) Comparison of the different structures for using in the
artificial reefs.
For the reason that there is a need to study and investigate the effects
of artificial reefs in large scale and obtain best results, 9 stations (3
treatments) will be selected at three depths (10±3, 20±3, 30±3 m) in costal waters of Hormozgan Province
in northern waters of the Persian Gulf, Iran. Fig. 5. These stations are
located in Bandar-e-Lengeh region. Each depth consists of 3 stations, (2
replicates and one reference site). Therefore in total 9 stations will be
studied. (Table 1 )
|
Different depth stations |
||||
|
Replicates stations |
Stations |
Depth 10 m |
Depth 20 m |
depth 30 m |
|
1st |
A1 |
B1 |
C1 |
|
|
2nd |
A2 |
B2 |
C2 |
|
|
|
3rd Reference site |
A3 |
B3 |
C3 |
Table 1.
– 3 depths (treatments) each one consist 3 stations or replicates
(2 reef stations &1reference station or
site)
In this project we will provide:
(a) Two kinds of designed and constructed
reefs e.g. Reef ball and Fish haven with an average weight of 1.5 tons (fig.
1-2).
(b) Out used materials, e.g. concrete,
column, metals, old vehicles, beg and old
pipes with the average weight 2 tons, total numbers 600
pieces according to attached table (table No. 2).
This study include the following steps:
(3-1)
Preliminary study before establishing of artificial reefs.
(3-2) Design, build and preparing the structures for artificial
reefs.
(3-3)
Transporting and deployment the structures in the sea.
(3-4)
Sampling and study after creating the artificial reefs.
3-1- Preliminary study before establishing of artificial reefs
(a) Determine suitable sites for
construction the structures
The best place to establish an artificial
reef site should have hard and strong sediment, in order to prevent sinking of
artificial structures in ooze or soil. The situation of the substrate and the
aquatic population in the sites will be assessed by direct observation through
SCUBA diving and sampling by trap and check in laboratory for identification of
aquatics to the genus and species level.
(b)
Determination of the compound and relative frequency of marine life in
stations.
The fishes around the reefs will be caught by three fishing
gears such as gillnet, trap and trawl in each stations twice a month to address
the compound and relative frequency as well as CPUE (Catch Per Unit Efforts) on
the basis of one of the following three methods:
(1) Catch per unit effort in spreading or surface.
(2) CPUE per day.
(3) CPUE in trap.
This data help in selection of target species and to make
comparison the catch before and after establishment artificial reefs.
(c) The
investigation of the possibilities for transporting the structures from coast
to stations in the sea. These are included: ports, roads, vehicles and tools
for building the structures.
(d) Recording
primary physical and chemical data of water in stations.
(e)
Determining the aim or purpose for choosing the species in search.
(f)
Underwater videography and photography in order to document the development and
rehabilitation of aquatics around and on
artificial reefs.
3-2-Desigen and building the artificial
reefs
The artificial reefs will be constructed
with the following :
(a) Reef ball and fish haven Fig. 1-2.
(b) Out used materials such as concrete,
broken bridges, old vehicles big and old pipes, and metals.
3-3-Transportaion
and deployment of structures
A qualified diver
team is necessary for deployment of structures in accordance with the attached
plan. Figure 3-4. After deployment of
artificial reefs some physicochemical properties of water including pH,
salinity, temperature and dissolved oxygen as well as biological data on
biodiversity of aggregated fish around the artificial reef and data on
planktons and benthos will be collected.
Preparing the plan to
construct the reefs: This project needs to have a temporal and spatial plan for
deployment of reefs. Fig.3- 4.
Preparing the big buoyant vehicles such as
barge, tow boat, boats, for using during the construct the reefs.
To deploy the structures in the selected
stations: The diver team will position the stations according to the determined
plans.
Underwater videography and photography: This will be carried out during
all practices including pre- and post-deployment.
Inspection of quality or circumstance (manner) to take in to
consideration all of the actions from coast to under water.
3-4
Underwater study of artificial reef.
One of the very
important parts of this project is to study the structures after deployment in
the sea over a 24 months period to check out the following issues:
(a) Measurement of physico-chemical
properties:
These factors
include: Temperature, Salinity, pH, Dissolved Oxygen, Nitrite, Phosphate,
Chlorophyll a, Turbidity, Grain size, Benthic or substrate (benthos) and
TOM (total organic matter).
Temperature (both air and water) will be measured in three
points around each station in each month.
Salinity
will be measured in three points around each station in each month.
pH each month from surface and bottom.
Dissolved Oxygen will be measured each month from surface and bottom by Oxygen meter.
Nitrite and
Phosphate: These factors are
two main parameters indicating the nutrients situation in the sea. These are
based on the food chain for producing in the sea.
Turbidity will be measured with spectrophotometer and Secchi Disc.
(b)
Identification and biometry.
Once the reefs
are deployed, many aquatic organisms will start to settle on these structures
as a base and habitat. These organisms will be collected in order to study
their biodiversity to the genus and species level and to determine their
relative frequency. These are mainly demersal fishes, mollusk (bivalves,
planktons,
Cephalopods…),
echinoderm (cucumber, sea stars…), crustacean (shrimps, barnacles, craps … ), sea worms (polychaetes …),marine algae or
sea weeds,
ichthyoplankton
and other macro and micro benthos and benthic.
Sampling of
fishes: Sampling from fish will be undertaken using
three gillnets and 9 traps in each station in a seasonal interval for the
duration of two years.
Macro-organisms
settled on the structures such as some bivalves, barnacles, algae, corals,
sponges, and etc. will be detached from reef surface and be transferred to
laboratory for identification and to determine their relative frequency.
Sampling from
benthos will be carried out using the grab at 3 points in each station in each
season for the identification purposes. In addition, the total organic matter
of substrate (TOM) will be determined according to grain size.
Sampling of planktons: phyto and zooplanktons will be colleted using a plankton net
with 55 microns mesh from surface and
bottom in each month.
Sampling of ichthyoplanktons: will be colleted using net(300-500 micron mesh) from the surface to the bottom.
References Cited:
B erger T.,J. McGurrin,and R.Stone. 1994. An
assessment of coastal artificial reef development in the United States.
Bulletin of marine science 55(2-3): 1328.
Bohnsack,J.A.,
D.L. Johnson and R.A. Ambrose. 1991.Ecology of artificial reef habitats and
fishes. Pages 61-107.In: W. Seaman, Jr. and L.M.Spargus, eds. Artificial
Habited For Marine and Freshwater Fisheries. Academic Press, San Diego.
Fabi, G and L.
Fiorentini. 1994. Comparison between an artificial reef and a control site in
the Adriatic Sea: analysis of four years monitoring . Bulletin of Marine Scince
55(2-3):538-558
Hagion, S. i991
Fishing effectiveness of the artificial reef in Japan. Page 119- 126. In: M
Nakamora, R. S. Grove, and C.J.Sonu, eds. Recont Advances in Aquatic
Habitate Technology Proceedings,
Japan-U.S Symposium on Artificial Habits For
Fisheries. Southern California Edison Co., Environmental Research Report
Series 91-RD-19, Rosemead, CA.
Omar, R. M. N. R.,
C.E. Kean, S. Wagiman , A.M.M. Hassan, M. Hussein, B.R. Hassan,and
C.O.M.Hussiu. 1994. Design and
construction of artificial reef in Malaysia. Bulletin of Marine Science
55(2-3): 1050-1061.
Ozasa, H., K.
Nakase, A. Watanuki, and H. Yamamoto.
1995. Structures accommodating to marine organisms. Page 406-411. In: H. Sako,
ed. Proceeding, International Conference O Ecology System Enhancement
Technology For Aquatic Environments.
Japan International Marine Science and Technology Federation Tokyo.
Rostamian, H.
1995 Study on establishment of artificial reefs in the costal waters of
Bushehr, Iran . Final report. Fisheries Research Organization Press. 85
pp.
Seaman, W. 2000.
Artificial reef evaluation with application to natural marine habitats. CRC
press. Washington DC. 246 pp.
Wilding, T. A.
and Sayer, M.D.j. 2002. Evaluating
artificial reef performance: approaches to per and post - deployment research.
ICES Jurnal of marine scince , 59: S 222-s 230.
Table 2. technical charactristic of marine
artificial reefs in the Persian Gulf of Iran
|
|||||
|
No. |
name |
weight t. |
size m. |
quantity no. |
kind |
|
1 |
reef ball |
I-1.5 |
1.5*1.5*1.2 |
50 |
concrete |
|
2 |
fish haven |
I-1.5 |
1.5*1.5*1.2 |
50 |
concrete |
|
3 |
out used material |
different weight |
different size |
100 |
broken and old concrete, metals, column, meshes, ships and pipes |

Figure 3. Map of the region(Bandar Lenggeh-Iran)
located stations.