Diamensions
–SV “SAMUDDRICA”
Length: 25 m
Draught: 1.7m
Engines: 2X 450hp
1X 250hp
Equipment List
Equipment
1. Acoustic Doppler Current Profiler (ADCP) –RDI Instrument -100m.
2. Side Scan Sonar –Yelowfin – 150m
3. Multibeem Echosounder –Reson seabat 8101-300m.
4. Sub bottom profiler-INNOMAR- 300m Sub bottom 25m
5.RCM current meters – 03
6.Grab Sampler 24kg ,5kg.
7. Rossette Water sample with CTD – 3000m
8.Single beam Echo sounder – 300m.
9. Trawling winch – 400m.
10.A Frame- 1000kg.
11. Side crane – 500kg.
Accommodation – 6 scientist + 6 crew members for additional personal insurance to be
obtained .
Endurance -5days
Speed – 17 knots
Survey speed – 5-6 knots
Communication – Inmarsat – telephone broadband , fax, radar ----ect
Dry lab
Wet lab ,
Rosette water sampler
The Rosette sampler is the primary sampling instrument for the collection of all Nutrient
parameters, phytoplankton, chlorophyll a, phaeophytin a, and dissolved oxygen from the
Biological Category, and temperature, total suspended solids, turbidity, specific
conductance, and pH from the Physical Category.
Water sampling devices range from a bucket dropped over the side of a small boat to
large water bottles sent toward the deep ocean seafloor on a wire. Probably the most
commonly used water sampler is known as a rosette. It is a framework with 12 to 36
sampling bottles (typically ranging from 1.2- to 30-liter capacity) clustered around a
central cylinder, where a CTD or other sensor package can be attached.
A 12-bottle Rosette sampler system (Sea-Bird Electronics 32 Carousel Water Sampler)
will be used to collect water samples. This equipment allows an operator to remotely
actuate a sequence of up to 12 water sampling bottles. This system consists of a CTD
(conductivity, temperature and depth sensor - Sea-Bird Electronics Model 9 Underwater
Unit) attached at the bottom of the Rosette, an A-frame, 1000 feet of multi-conductor
cable, a variable speed winch and Sea-Bird Electronics Model 11 Deck Unit with
attached computer. The CTD measures water depth and temperature, which is
graphically (CRT) displayed onboard the research vessel. The bottles can be closed in
any predetermined order, remotely from the deck of the vessel while the array is
submerged at the various sampling depths. The Rosette sampler is equipped with 8 L
Niskin bottles.
The depth at which samples will be collected is detected by a pressure transducer on the
CTD. To assure that the display parameters are set to include the entire water column,
the Rosette winch operator obtains a depth sounding from the bridge and writes this on
the Rosette form, then adjusts the computer program parameters controlling the depth
range to be displayed (See “Instructions for use of the Sea-Bird 9/11+...”). The Rosette
sampler will then be lowered to the bottom at between .5 and 1 meter/second, raised at
least 5 meters after contacting the bottom. The operator will wait three minutes to allow
the sampler to drift away from the disturbed area before the B-2 (2 meters up from the
bottom) sample is
taken. The Rosette
sampler will be
lowered to B-2 and the
sample taken.
Additional
time
intervals of three
minutes are allowed
to elapse prior to
taking
the
thermocline
sample
and
the
lower
epilimnion
sample.
These
intervals
provide time for water
equilibration within
the Niskins.
The knees of the EBT temperature depth trace will be determined by trisecting the angle
between the epilimnion and mesolimnion temperature traces (upper knee) and the angle
between the mesolimnion and hypolimnion temperature traces (lower knee). The upper
knee is the upper a angle intercept, the lower knee is the lower a angle intercept. The
lower epilimnion sample is one meter above the upper knee. The upper hypolimnion
sample is one meter below the lower knee.
Nansen bottles
A Nansen bottle is a device for obtaining samples of seawater at a specific depth.
The bottle, more precisely a metal or plastic cylinder, is lowered on a cable into
the ocean, and when it has reached the required depth, a brass weight called a
"messenger" is dropped down the cable. When the weight reaches the bottle, the impact
tips the bottle upside down and trips a spring-loaded valve at the end, trapping the water
sample inside. The bottle and sample are then retrieved by hauling in the cable.
A second messenger can be arranged to be released by the inverting mechanism, and
slide down the cable until it reaches another Nansen bottle. By fixing a sequence of
bottles and messengers at intervals along the cable, a series of samples at increasing
depth can be taken.
The sea temperature at the water sampling depth is recorded by means of a reversing
thermometer fixed to the Nansen bottle. This is a mercury thermometer with a
constriction in its capillary tube which, when the thermometer is inverted, causes the
thread to break and trap the mercury, fixing the temperature reading. Since
water pressure at depth will compress the thermometer walls and affect the indicated
temperature, the thermometer is protected by a rigid enclosure. A non-protected
thermometer is paired with the protected one, and comparison of the two temperature
readings allows both temperature and pressure at the sampling point to be determined.
Ruttner sampler
Ruttner water Sampler can be used for limnological and hydro- biological investigation.
It is employed in the water column at various depths in order to obtain water for the
analysis of nutrients and pollutants. Plankton is sampled with a tube in order to allow for
sampling over the entire water depth and in different areas.
Grab Sampler
Azmy : This sampler is designed to collect an accurate representative sample of the
sediment bottom. The bite of the sampler should be deep enough so all depths are
sampled equally. The closing mechanism is required to completely close and hold the
sample as well as prevent wash-out during retrieval.
On the website : These samplers are designed to collect an accurate representative sample
of the sediment bottom. The bite of the sampler should be deep enough so all depths are
sampled equally. The closing mechanism is required to completely close and hold the
sample as well as prevent wash-out during retrieval.
http://www.rickly.com/as/bottomgrab.htm
Plankton Net
Azmy : Plankton Nets are a modification on the standard trawl used to collect planktonic
organisms, of nearly any size, intact. Towed by a research vessel, the Plankton Nets have
a long funnel shape that allows them to catch differently sized plankton simply by
changing the mesh size of the net.
http://www.vliz.be/wiki/Sampling_tools_for_the_marine_environment
On the web site : Plankton nets are a modification on the standard trawl used to collect
planktonic organisms, of nearly any size, intact. Towed by a research vessel, plankton
nets have a long funnel shape that allows them to catch differently sized plankton simply
by changing the mesh size of the net.
zooplanktons under microscope
_________________________________________
Primary productivity, Nutrients and Pollution
Primary productivity is a term used to describe the rate at which plants and other
photosynthetic organisms produce organic compounds in an ecosystem. There are two
aspects of primary productivity: Eutrophication is the “excess supply of nutrients leading
to increased biological productivity”
The nutrients found in seawater are essential to the survival of plant and marine life.
Phosphate, Nitrate- Nitrogen, Nitrite- Nitrogen and Ammonical- Nitrogen are the main
nutrients measured for analysis of sea water.
Pollution in the ocean directly affects ocean organisms and indirectly affects human
health and resources. Oil spills, toxic wastes, and dumping of other harmful materials are
all major sources of pollution in the ocean.
Samples of seawater for determining the above factors can be obtained with Ruttner
sampler, Nansen bottles and rosette sampler. Bottom grab sampler can be used for
collecting of sediments.
Research projects in Environmental Studies Division using the NARA ship –
Samudrika
The main activity of Environmental Studies Division to conduct research with
respect to the inland, coastal and marine aquatic environment. Studies involve
marine pollution surveys including land based pollution surveys, plankton sampling
to identify native plankton species assessment of health of the ocean, Plankton
distribution in accordance with water quality parameters, assessment of
agricultural input to the water quality of inland and coastal waters, accumulation of
heavy metals in aquatic fauna and flora etc;
The main objective of the above research projects are for sustainable development
and utilization of water resources to improve the health of the aquatic environment
and assist in the development of fisheries and aquatic resources.
During this year (2012) the division is conducting three main research projects to
monitoring the aquatic health to develop the fisheries and aquatic resources.
1. Emergency Studies (Assessment of Causes for Water pollution, Fish kill
incidents,oilspills & Algal blooms
2. Investigation on alien aquatic fauna & flora(phytoplankton & zooplankton) in
ballast waters and study their impacts on water quality with special
reference to economic & human health aspects
3. Assessment of land based pollution and coastal aquatic health - monitoring
of coastal water quality from Negombo-Bentota to improve the health of the
seas around western province)And, the next year projects will include assessment of health of the ocean –Coastal
Water quality monitoring programme which will be carried out in the ocean waters
from the continental shelf area to the off shore using different depths and distances.
This project is planning to carry out Colombo,Galle,Matara,Hambantota,Trincomalle
,Mannar and Batticoloa Districts.
Recent research findings revealed that fecal pollution of our coastal waters exceed
the standard limits /permissible levels specially the total and fecal coliform levels.
Fecal pollution is a major problem in some coastal waters due to the direct
discharge of untreated municipal sewage into land and waterways. Many highly
populated coastal low-lying areas have a shallow water table and a high
vulnerability for flooding. Inadequate drainage facilities and adhoc development in
these areas have further intensified the impacts of inappropriate sewage disposal in
low-lying flood prone coastal areas leading to severe fecal pollution in internal and
near shore waters.
Therefore one of future research activities of the division aims assessment of ocean
health with special reference to microbiological analysis of water quality
monitoring.
The other research projects of the division involve plankton sampling to identify
native plankton species and Plankton distribution in accordance with water quality
parameters. Plankton are the productive base of both marine and fresh water
ecosystems, providing food for large animals and indirectly for human, whose
fisheries depends on plankton. Zooplankton are used directly as food by fish or
mammals, but several links on the food chain usually have been fast before plankton
is available for human consumption.
The introduction of invasive marine species into new environments by ships’ ballast
waters attached to ships’ hulls and via other vectors has been identified as one of
the four greatest threats to the world’s oceans. Coastal port areas are home to a
wide variety of organisms that live in the water and bottom sediments.
Some of the species that do survive the trip are able to thrive in their new
environment. These bioinvaders can cause disruptions in the natural ecosystem,
economic troubles, and even carry human diseases. Many aquatic invasive species
can cause major economic impacts on human society.
Direct economic losses to society can be caused by aquatic bio-invasions in a
number of ways, including reductions in fisheries production (including collapse of
the fishery) due to competition, predation and/or displacement of the fishery
species by the invading species, and/or through habitat/environmental changes
caused by the invading species and impacts on aquaculture (including closure of
fish-farms), especially from introduced harmful algae blooms. And also Secondary
economic impacts from human health impacts of introduced pathogens and toxic
species, including increased monitoring, testing, diagnostic and treatment costs, and
loss of social productivity due to illness and even death in affected persons.
Therefore one of our projects aims identifying alien aquatic fauna & flora
(phytoplankton & zooplankton) in ballast waters and studies their impacts on water
quality with special reference to economic & human health aspects and also to
identify whether there is any impacts on fisheries and aquaculture to management
of fisheries and aquaculture.
ADCP and CTD
The research Vessel RV/ Samudrikabelong to National Aquatic Resources Research and
Development Agency (NARA) equipped with Acoustic Doppler Current Profiler (ADCP)
and Conductivity Temperature Depth (CTD) profiler to measure physical oceanographic
parameters such as current velocity, temperature and conductivity of water column.
Those instruments are advance technologies which can be utilised in oceanographic
applications.
ADCP
The RV/Samudrika equipped with hull mounted ADCP which can be used to measure
sound velocity profiles towards down (downward looking). The instrument set in the ship
as given in the diagram 1. The data bins are designed at 2.5m from the instrument up to
35meters with 1m bin intervals. The instrument consists of four beam transducers
transmits a pulse of energy along beam directions inclined typically at 30 degrees from
the vertical.Particles in the water column and in homogeneities reflect some sound energy
back to the transducer. The motion of the reflectors relative to the transducer causes a
Doppler shift in the frequency of the received echo. On average these particles will move
at the average velocity of the water surrounding them. Therefore, we can determine the
velocity component along each beam at any point from the Doppler shift. In practice, we
use the echoes returning at later and later times to determine the velocity component
further and further from the transducer. By combining the measurements from the 3 or 4
beams we can calculate the horizontal and vertical components of velocity at different
depths. So, it provides the current velocity profiles in different depth levels. The data can
be utilised to study the generation of internal waves, surface friction velocity and the
stress.
Fig.1 Ship mounted ADCP in Samudrika
Conductivity Temperature Depth Profiler
Fig.2 Operation of CTD with Rosette water sampler
CTD profiler measures variation of Conductivity and Temperature of sea water as a
function of Depth. Conductivity is important parameter because it determines the
dissolved salts in the sea water. From the conductivity, temperature and depth of any
measurement we can calculate the salinity, density and other properties that allow us to
trace movement and processes such as mixing in the ocean.
The vessel Samudrika equipped with seabird9plus and 19plus CTD’s. The instruments
have capacity to take measurements from top to 3000m and 600m respectively. The
available sensors allows to measure, conductivity, temperature, density, dissolved oxygen
and chlorophyll. Those parameters can be utilized to study the oceanic processes, fish
forecasting and seasonal variation of thermocline depths. In addition to the CTD, the
vessel equipped with the 2000m long coaxial cable and winch to operate the instrument.
The figure 2 illustrates the CTD operation with rosette water samplers.
Side scan sonar investigations
Side scan sonar is mainly used for detection of underwater objects such as sunken ships,
aero planes, pipe lines, and geo-morphological features on the sea bed. Main advantages
of this technology are time effective for searching, safe deep water operations and large
spatial coverage within short time. In addition, this gives chance to work in more risky
environments even in murky or black waterless visibility. The lack of good last observed
point, information can extend the search area to tens or hundreds of square kilometers
instead of small area. In many cases there are no accurately identified locations where the
drowning objects last observed. Therefore side scan sonar can effectively use under these
conditions.
RV/ Sumudrikaarealso equipped with Yellowfin side scan sonar. It is an instrument with
triple frequencies. The instrument has two data acquisition cables with 30m and 150m
length respectively. Currently, the instrument is used for offshore sand deposit and
underwater heritage (shipwrecks) investigation around the country.
Underwater heritage investigations
Side scan sonar is a very good instrument to locate underwater heritages specially in
shipwreck investigations around the country. Some findings from NARA research team is
given in the diagram.
Fig. Some shipwrecks found in east coast of Sri Lanka
Sand depositsinvestigation
Side scan sonar is an important instrument for sand deposits. Some side scan sonar
images are given in the following diagrams.
Underwater pipe line investigation
Fig. Side scan images from east coast of Sri Lanka
Moorings and Profiling
The vessel Sudrika is equipped with three winches. One is with 2000m coaxial cable to
be used for CTD deployments and other two with 100m and 300m fibre optic cable used
for offshore coring and trawling respectively. The possible deployments and moorings
will be discussed as follows.
Deployment of Drifters and Argoprofilers
RV/ Samudrika have enough deck space, winch and A-Frame facilities for Drifter and
Argo float deployments. Currently, NARA engaging drifter deployments but new
research vessel will increase efficiency of the deployments. The diagrams show the
drifter and Argo deployments by NARA Oceanographic research team.
Fig: Drifter and Argo deployment in the offshore southern Sri Lanka
ADCP moorings
Samudrika can be utilised for shallow water Acoustic Doppler Current Profiler (ADCP)
moorings around the continental shelf of Sri Lanka. A-Frame belongs to vessel can be
used for this moorings. Some ADCP moorings are given in the diagrams.
Fig. ADCP moorings
Geological and Geophysical Exploration of Continental shelf
Recognizing the importance of the marine sciences, Oceanography Division of NARA is
conducting research and surveys within the continental shelf of Sri Lanka. Geological
and Geophysical exploration initiated by NARA include the investigation of heavy
minerals and stratigraphic variations beneath the sea floor mainly in coastal and offshore
regions.
Sub Bottom Profiling
Sub-bottom profiling systems identify and measure various marine sediment layers that
exist below the sediment/water interface. Anenergy source emits seismic signal vertically
downwards into the water and a receiver monitors the return signal that has been reflected
off the seafloor. The system uses this reflected energy to provide information on sediment
layers beneath the sediment-water interface.
Capabilities
Sub-bottom profiling systems useful for characterizing benthic habitats, since they
provide information about sub-surface sediment structure. No other techniques provide
this type of information, and only physical sampling via cores will allow for
characterization of subsurface structures.
Uses




Detect and measure the thickness of dredged material deposits.
Detect hard substrate that has been covered by sedimentation.
Identify buried objects (such as cables and pipelines).
Define the basement (or bedrock) layer for potential confined aquatic disposal
sites for dredged material.
Fig. Illustrate the sub-bottom profiling apparatus and survey results
Geological Exploration
Oceanography division is mainly conducting geological exploration for study surface
geological variations and placer mineral surveys for identifying economically potential
areas for mining. Some sampling devices and separation equipment’s are given in the
diagram.
Fig. Wet lab apparatus to be used in onboard sample collection and analysis
Around the world, fisheries scientists are increasingly recognizing ecosystems as natural
capital assets. Scientific understanding of ecosystem production function is improving
rapidly in many parts of the world but in Sri Lanka it remains a due to limitation of
research facilities especially a research vessel. Even though, seas around Sri Lanka have
unique geographical and hydrological characteristics to support various fisheries, the
distribution, potential resources, stock assessments and catch targets are not properly
identified in many fisheries. The research vessel “Sagarika” will be a unique platform to
fisheries scientists to find out the information gap by carrying out their research in the
ocean. These information will lead to explore new resources as well as management and
conservation of new resources.
A marine research can be used in mainly
1. To understand physical and chemical oceanographic and hydrological conditions
2. To investigate the stock size, abundance, distribution, size of maturity, feeding habits
etc of economically and ecologically important marine resources
3. To assess potential fishery resources
There are several methods of experimental fishing can be used in research vessels.
Trawling
Trawling is one of the most common methods of sampling bottom or pelagic resources in
the sea. Trawling involves towing one or more trawl nets behind a boat or in between two
boats, either through the water column or along the ocean’s floor. Trawl nets are usually
shaped like a cone or funnel with a wide opening to catch fish or crustaceans and a
narrow closed end called a cod-end. Trawls can be used in water of various depths down
to around 3000m, and nets differ by their mesh size.
i. Mid water trawl
Midwater trawls can be used to sample in
the water column and are used to catch a
variety of pelagic fish species. Sometimes,
may use paired trawls, where two boats
pull one net. Midwater trawl nets may
incorporate acoustic technology to tell the
scientists the position of the net in the
water column, the opening/spread of the net
and the volume of fish entering the net.
Additional instruments on the net can
record the speed at which the net is
traveling. Both demersal and midwater
trawls use otterboards to keep the mouth of
the net open.
ii. Demersal Trawl
Demersal trawls are used to sample fish,
prawns or others that live on the bottom of
the ocean. Trawlers targeting finfish often
use one net (this is called a single trawl) or
two nets (twin trawl), whereas prawn
trawlers may use a twin-rig (towing two
nets) or quad-rig (towing four nets).
Squid Jig
Squid jigging can be carried out using
either mechanically powered or hand
operated
jigs.
Overhead
lights
illuminate the water and attract the
squid which gather in the shaded area
under the boat. Squid are caught using
barbless lures on fishing lines which are
jigged up and down in the water. Using
barbless lures means that as the lures
are recovered over the end rollers, the
squid fall off into the boat.
Longlines
Longlines are set horizontally either on the ocean floor (demersal longlines) or near the
surface of the water (pelagic longlines). Longlines can be tens of kilometres long and
carry thousands of hooks. Baited hooks are attached to the longline by short lines called
snoods that hang off the mainline.
Pelagic longlines are set near the
surface or middle of the water column.
Longlines can be many kilometres
long and carry thousands of hooks.
Pelagic longlines are not anchored and
are set to drift near the surface of the
ocean with a radio beacon attached so
that the vessel can track them to haul
in the catch. Pelagic longlines are
Figure: Longline operations at a research vessel
Plankton Research
Other than the research on fish, plankton studies are often carried out using research
vessels. These tiny organisms are the food sources of many economically important
species. Similarly, the research can be carried out to examine the abundance and
distribution of fish eggs and larvae in the ocean.
Figure: Sampling of zooplankton using a plankton net and a view of plankton sample
under a microscope