Capture fishery : Marine and Inland Fisheries

“Capture fishery refers to all kinds of harvesting of naturally occurring living resources in both marine and freshwater environments.”
Capture fisheries is intended for catching fishes, prawns, lobsters, crabs, molluscs etc. India is endowed with vast and varied aquatic resources (Marine and Inland) amenable for capture fisheries. India is the Second largest producer of fish after the China and also second largest producer of inland fish in the world.

1. Marine Fisheries
2. Inland Fisheries

(Marine and Inland Fisheries)

1. Marine Fisheries –

Central Marine Fisheries Research Institute (CMFRI)
The Central Marine Fisheries Research Institute was established by Government of India on February 3 1947 under the Ministry of Agriculture and Farmers Welfare and later it joined the ICAR family in 1967. During the course of over 65 years the Institute has emerged as a leading tropical marine fisheries research institute in the world.

Headquarters of CMFRI – Kochi Kerala.

 PELAGIC FISH-

Pelagic fish live in the pelagic zone of ocean or lake waters – being neither close to the bottom nor near the shore – in contrast with demersal fish, which do live on or near the bottom, and reef fish, which are associated with coral reefs The marine pelagic environment is the largest aquatic habitat on Earth, occupying 1,370 million cubic kilometres (330 million cubic miles), and is the habitat for 11 percent of known fish species. The oceans have a mean depth of 4000 metres. About 98 percent of the total water volume is below 100 metres, and 75 percent is below 1000 metres.

Marine pelagic fish can be divided into pelagic coastal fish and oceanic pelagic fish. Coastal fish inhabit the relatively shallow and sunlit waters above the continental shelf, while oceanic fish (which may well also swim inshore) inhabit the vast and deep waters beyond the continental shelf. Pelagic fish range in size from small coastal forage fish, such as herrings and sardines, to large apex predator oceanic fishes, such as the Southern bluefin tuna and oceanicsharks. They are usually agile swimmers with streamlined bodies, capable of sustained cruising on long distance migrations.

The Indo-Pacific sailfish, an oceanic pelagic fish, can sprint at over 110 kilometres per hour. Some tuna species cruise across the Pacific Ocean. Many pelagic fish swim in schools weighing hundreds of tonnes. Others are solitary, like the largeocean sunfish weighing over 500 kilograms, which sometimes drift passively with ocean currents, eating jellyfish.

(Marine and Inland Fisheries)

Coastal fish

Coastal fish (also called neritic or inshore fish) inhabit the waters near the coast and above the continental shelf. Since the continental shelf is usually less than 200 metres deep, it follows that coastal fish that are not demersal fish are usually epipelagic fish, inhabiting the sunlit epipelagic zone. Coastal epipelagic fish are among the most abundant in the world.

They include forage fish as well as the predator fish that feed on them. Forage fish thrive in those inshore waters where high productivity results from the upwelling and shoreline run off of nutrients.
Some are partial residents that spawn in streams, estuaries and bays, but most complete their life cycle in the zone.

Oceanic fish

Oceanic fish inhabit the oceanic zone, which is the deep open water which lies beyond the continental shelves. Oceanic fish (also called open ocean or offshore fish) live in the waters that are not above the
continental shelf. Oceanic fish can be contrasted with coastal fish, which do live above the continental shelf. However, the two types are not mutually exclusive, since there are no firm boundaries between coastal and ocean regions, and many epipelagic fish move between coastal and oceanic waters, particularly in different stages in their life cycle. Oceanic epipelagic fish can be true residents, partial residents, or accidental residents.

True residents live their entire life in the open ocean. Only a few species are true residents, such as tuna, billfish, flying fish, sauries, commercial pilot fish and remoras, dolphin, ocean sharks and ocean sunfish. Most of these species migrate back and forth across open oceans, rarely venturing over continental shelves. Some true residents associate with drifting jellyfish or seaweeds. Partial residents occur in three groups: species which live in the zone only when they are juveniles (drifting with jellyfish and seaweeds); species which live in the zone only when they are adults (salmon, flying fish, dolphin and whale sharks); and deep water species which make nightly migrations up into the surface waters (such as the lantern fish).

(Marine and Inland Fisheries)

Ocean sunfish

The huge ocean sunfish, a true resident of the ocean epipelagic zone, sometimes drifts with the current, eating jellyfish.

Whale shark

The giant whale shark, another resident of the ocean epipelagic zone, filter feeds on plankton, and periodically dives deep into the mesopelagic zone.

Lantern fish

Lantern fish are partial residents of the ocean epipelagic zone. During the day they hide in deep waters, but at night they migrate up to surface waters to feed

(Marine and Inland Fisheries)

Epipelagic fish

`Large epipelagic predator fish, like this Atlantic blue fin tuna, have a deeply forked tail and a smooth body shaped like a spindle tapered at both ends and counter shaded with silvery colours. Small epipelagic forage fish, like this Atlantic herring, share the same body features listed for the predator fish above. Epipelagic fish inhabit the epipelagic zone. The epipelagic zone is the water from the surface of the sea down to 200 metres. It is also referred to as the surface waters or the sunlit zone, and includes the photic zone. The photic zone is defined as the surface waters down to the point where the sunlight has attenuated to 1 percent of the surface value. This depth depends on how turbid the water is, but in clear water can extend to 200 metres, coinciding with the epipelagic zone. The photic zone has sufficient light for phytoplankton to photosynthese.

The epipelagic zone is vast, and is the home for most pelagic fish. The zone is well lit so visual predators can use their eyesight, is usually well mixed and oxygenated from wave action, and can be a good habitat for algae to grow. However, it is an almost featureless habitat. This lack of habitat diversity results in a lack of species diversity, so the zone supports less than 2 percent of the world’s known fish species. Much of the zone lacks nutrients for supporting fish, so epipelagic fish tend to be found in coastal water above the continental shelves, where land runoff can provide nutrients, or in those parts of the ocean where upwelling moves nutrients into the area.

(Marine and Inland Fisheries)

Epipelagic fish can be broadly divided into small forage fish and larger predator fish, which feed on them. Forage fish school and filter feed on plankton. Most epipelagic fish have streamlined bodies capable of sustained cruising on migrations. In general, predatory and forage fish share the same morphological
features. Predator fish are usually fusiform with large mouths, smooth bodies, and deeply forked tails. Many use vision to predate zooplankton or smaller fish, while others filter feed on plankton.
Most epipelagic predator fish and their smaller prey fish are counter shaded with silvery colours, which reduce visibility by scattering incoming light. The silvering is achieved with reflective fish scales that function as small mirrors. This can give an effect of transparency. At medium depths at sea, light comes from above, so a mirror oriented vertically makes animals such as fish invisible from the side.
In the shallower epipelagic waters, the mirrors must reflect a mixture of wavelengths, and the fish accordingly has crystal stacks with a range of different spacings. A further complication for fish with bodies that are rounded in cross-section is that the mirrors would be ineffective if laid flat on the skin, as they would fail to reflect horizontally. The overall mirror effect is achieved with many small reflectors, all oriented vertically.

(Marine and Inland Fisheries)

Though the number of species is limited, epipelagic fishes are abundant. What they lack in diversity they make up in numbers. Forage fish occur in huge numbers, and large fish that predate on them are often sought after as premier food fish. As a group, epipelagic fishes form the most valuable fisheries in the world. Many forage fish are facultative predators that can pick individual copepods or fish larvae ou t of the water column, and then change to filter feeding on phytoplankton when energetically that gives better results. Filter feeding fish usually use long fine gill rakers to strain small organisms from the water column. Some of the largest epipelagic fishes, such as the basking shark and whale shark are filter feeders, and so are some of the smallest, such as adult sprats and anchovies.

Ocean waters that are exceptionally clear contain little food. Areas of high productivity tend to be somewhat turbid from plankton blooms. These attract the filter feeding plankton eaters, which in turn attract the higher predators. Tuna fishing tends to be optimum when water turbidity, measured by the maximum depth a secchi disc can be seen during a sunny day, is 15 to 35 metres.

(Marine and Inland Fisheries)

Floating objects
Drifting Sargassum seaweed provides food and shelter for small epipelagic fish. The small round spheres are floats filled with carbon dioxide, which provide buoyancy to the algae.
Epipelagic fish are fascinated with floating objects. They aggregate in considerable numbers around objects such as drifting flotsam, rafts, jellyfish and floating seaweed. The objects appear to provide a “visual stimulus in an optical void”. Floating objects can offer some protection for juvenile fish from predators. The availability of lots of drifting seaweed or jellyfish can result in significant increases in the survival rates of some juvenile species.
Many coastal juveniles use seaweed for the shelter and the food that is available from invertebrates and other fish associated with it. Drifting seaweed, particularly the pelagic Sargassum, provide a niche habitat with its own shelter and food, and even supports its own unique fauna, such as the sargassum fish.

(Marine and Inland Fisheries)

 DEMERSAL FISH

Demersal fish live and feed on or near the bottom of seas or lakes (the demersal zone). They occupy the sea floors and lake beds, which usually consist of mud, sand, gravel or rocks. In coastal waters they are found on or near the continental shelf, and in deep waters they are found on or near the continental slope or along the continental rise. They are not generally found in the deepest waters, such as abyssal depths or on the abyssal plain, but they can be found around seamounts and islands. The word demersal comes from the Latin demergere, which means to sink.

Demersal fish are bottom feeders. They can be contrasted with pelagic fish which live and feed away from the bottom in the open water column. Demersal fish fillets contain little fish oil (one to four percent), whereas pelagic fish can contain up to 30 percent.

(Marine and Inland Fisheries)

Types of Demersal fish

Demersal fish can be divided into two main types: strictly benthic fish which can rest on the sea floor, and benthopelagic fish which can float in the water column just above the sea floor.

 Benthic fish, sometimes called groundfish, are denser than water, so they can rest on the sea floor.
 Benthopelagic fish inhabit the water just above the bottom, feeding on benth os and zooplankton.
 Benthopelagic fish have neutral buoyancy, so they can float at depth without much effort, while strictly benthic fish are more dense, with negative buoyancy so they can lie on the bottom without any effort. Most demersal fish are benthopelagic.

(Marine and Inland Fisheries)

As with other bottom feeders, a mechanism to deal with substrate is often necessary. With demersal fish the sand is usually pumped out of the mouth through the gill slit. Most demersal fish exhibit a flat ventral region so as to more easily rest their body on the substrate.

The exception may be the flatfish, which are laterally depressed but lie on their sides. Also, many exhibit what is termed an “inferior” mouth, which means that the mouth is pointed downwards; this is beneficial as their food is often going to be below them in the substrate. Those bottom feeders with upward-pointing mouths, such as stargazers, tend to seize swimming prey.

Coastal demersal fish are found on or near the seabed of coastal waters between the shoreline and the edge of the continental shelf, where the shelf drops into the deep ocean. Since the continental shelf is generally less than 200 metres deep, this means that coastal waters are generally epipelagic. The term includes demersal reef fish and demersal fish that inhabit estuaries, inlets and bays.

(Marine and Inland Fisheries)

DEEP SEA FISH

Deep-sea fish are fish that live in the darkness below the sunlit surface waters, that is below the epipelagic or photic zone of the ocean. The lantern fish is, by far, the most common deep-sea fish. Other deep sea fish include the flashlight fish, cookie cutter shark, bristle mouths, anglerfish, and viperfish. Only about 2% of known marine species inhabit the pelagic environment. This means that they live in the water column as opposed to the benthic organisms that live in or on the sea floor.Deep-sea organisms generally inhabit bathypelagic (1000m-4000m deep) and abyssopelagic (4000m-6000m deep) zones. However, characteristics of deep-sea organisms, such as bioluminescence can be seen in the mesopelagic (200m-1000m deep) zone as well. The mesopelagic zone is the disphotic zone, meaning light there is minimal but still measurable. The oxygen minimum layer exists somewhere between a depth of 700m and 1000m deep depending on the place in the ocean.

This area is also where nutrients are most abundant. The bathypelagic and abyssopelagic zones are aphotic, meaning that no light penetrates this area of the ocean. These zones make up about 75% of the inhabitable ocean space. The zone that deep-sea fish do not inhabit is the epipelagic zone (0m-200m), which is the area where light penetrates the water and photosynthesis occurs. This is also known as the
euphotic, or more simply as the photic zone. Because the photic zone typically extends only a few hundred meters below the water, about 90% of the ocean volume is in darkness. The deep-sea is also an extremely hostile environment, with temperatures that rarely exceed 3°C and fall as low as -1.8°C” (with the exception of hydrothermal vent ecosystems that can exceed 350°C), low oxygen levels, and pressures between 20 and 1,000 atmospheres (between 2 and 100 megapascals.

(Marine and Inland Fisheries)

Environment

In the deep ocean, the waters extend far below the epipelagic zone, and support very different types of pelagic fishes adapted to living in these deeper zones. In deep water, marine snow is a continuous shower of mostly organic detritus falling from the upper layers of the water column. Its origin lies in activities within the productive photic zone. Marine snow includes dead or dying plankton, protists (diatoms), fecal matter, sand, soot and other inorganic dust. The “snowflakes” grow over time and may reach several centimetres in diameter, travelling for weeks before reaching the ocean floor. However, most organic components of marine snow are consumed by microbes, zooplankton and other filter-feeding animals within the first 1,000 metres of their journey, that is, within the epipelagic zone. In this way marine snow may be considered the foundation of deepsea mesopelagic and benthic ecosystems: As sunlight cannot reach them, deep-sea organisms rely heavily on marine snow as an energy source.
Some deep-sea pelagic groups, such as the lantern fish, ridgehead, marine hatchet fish, and lightfish families are sometimes termed pseudoceanic because, rather than having an even distribution in open water, they occur in significantly higher abundances around structural oases, notably seamounts and over continental slopes. The phenomenon is explained by the likewise abundance of prey species which are also attracted to the structures.

(Marine and Inland Fisheries)

Hydrostatic pressure increases by 1 atmosphere for every 10m in depth. Deep-sea organisms have the same pressure within their bodies that is being exerted on them from the outside, so they aren’t crushed by the extreme pressure. Their high internal pressure, however, results in the reduced fluidity of their membranes because molecules are squeezed together. Fluidity in cell membranes increases efficiency of biological functions, most importantly the production of proteins, so organisms have adapted to this circumstance by increasing the proportion of unsaturated fatty acids in the lipids of the cell membranes. In addition to differences in internal pressure, these organisms have developed a different balance between their metabolic reactions from those organisms that live in the epipelagic zone. David Wharton, author of Life at the Limits: Organisms in Extreme Environments notes, “Biochemical reactions are accompanied by changes in volume. If a reaction results in an increase in volume, it will be inhibited by pressure, whereas, if it is associated with a decrease in volume, it will be enhanced”. This means that their metabolic processes must ultimately decrease the volume of the organism to some degree.

2. Inland Fisheries

In India, inland fisheries is classified as follows: freshwater aquaculture, including the pond culture of carp; brackishwater aquaculture, involving mostly shrimp culture; and capture fisheries in rivers, estuaries, lakes, reservoirs, etc.

(Marine and Inland Fisheries)

Reverine Fisheries

India is blessed with vast inland water resources in the form of rivers, estuaries, natural and manmade lakes. The Inland water bodies have been divided into five riverine systems and their tributaries extending to a length of about 29,000 km in the country – Indus, Ganges, Bramhaputra, East flowing riverine system and West riverine system. All these rivers, their tributaries, canals and irrigation
channels have and area of roughly 13000km. These water bodies harbor the original germplasm of one of the richest and diversified fish fauna of the world comprising 930 fish species belonging to 326 genera. The major river systems of India on the basis of drainage can be divided broadly into two major rivers systems. They are…..

(i) Himalayan rivers system (Ganga, Indus and Bramhaputra) and
(ii)Peninsular river system (East cost and West coast river system).

(Marine and Inland Fisheries)

Ganges River System :-

It is the largest river systems of the world, having a combined length (including tributaries) of 12,500 km. It originates from Gangotri in the Himalayas at a height of about 3129 km above the sea level. After origin it drains the southern slopes of the central Himalayas. Ganga passes through UP, Bihar, some parts of Rajasthan, M.P. and west Bengal and finally joins to the Bay of Bengal. It has a large number of tributaries and ‘Yamuna’ river is one of the major tributaries of this system, which is about 1000 km long. The other tributaries are –
Ram Ganga. Gomti, Ghaghra, Gandak, Kosi, Chambal, Betwa and Ken. Further more; it has numerous lakes, ponds and Jheels, both perennial and seasonal areas. It has a total catchment area of 9.71 lakh sq. km and receives an annual rainfall of 25-77 inches.

(Marine and Inland Fisheries)

Physico-Chemical Characteristics:-

i) Temperature range – 16.7°C in January – 31.5°C in June to sept.

ii) PH – 7.4 during June to August and Maximum 8.3 during January to May.

iii) Turbidity – 100 ppm in January; 1100-2170 ppm during July to September .

iv) Do2 – 5.0 to 10.5 ppm during January to February while in monsoon 2.00p pm (July-Sept.)

v) CO2 – 0.6 ppm -10.0ppm

vi) Chloride – 4.0 -35.4 ppm

vii) Phosphate – 0.05-021pp m

viii) Nitrates – 0.08-0.22ppm

ix) Silicates – 4.0-20.3ppm

x) Carbonates – 1.0 – 12.0 ppm

(Marine and Inland Fisheries)

Common Phytoplanktons:-

Phytoplanktons are generally poor during the monsoon and autam months. Common phytoplanktons found in Ganga river system are – (i) Members of Bacillariophyceae like Amphora, Asterionella, Cymbella, Navicula and Synedra etc. (ii) members of Chlorophycace like, Chlorella, Closterium, Denticula, Pandorina and Spirogyea etc.(ii) members of Myxophyceae like Anabaena, Nostoc, Oscillatoria etc.

Common zooplanktons:-

Rattulas, Rotaria, Keratella, Filuia, Notops, Monostyla etc

(Marine and Inland Fisheries)

Fisheries of Ganga river systems:-

The Ganga river system supports a large number of commercially important fish species including major carps (Labeo. rohita: L.Calabasu, Catla catla and Cirrhinus mrigala), minor carps ( Labeo fimbriatus; L.bata; Cirrhinus. reba), catfishes (Wallago. attu ; Mystus. aor; M.tengara, Clarias. batrachus; Heteropneustes fossilis), cluipeiods, murrels (Channa species), feather backs (Notopterus. notopterus; N.chitala), mullets (Mugil corsula), fresh water eel (Anguilla) and prawns (Macrobrachium malcolmsonii; Palaemon. Lamarii). Apart from these fishes, the others like Pangasius; silonia silondia; Gudusia chapra; Bagasius. bagasius; Eutropichthys. vacha are also found in the river system.
The commercial fisheries in this zone are non-existing due to spares population, inaccessible terrain and poor communication between fishing grounds and landing centers. The fish yield has been declined over the years due to

1) sandification of the river bed (upto Patna) which reduced the rivers productivity due to blanket effect,

2) marked reduction in the water volume on account of increase sedimentation,

3) increased water abstraction and

4) irrational fishing. In spite of this, the Ganga river system is contributing nearly about 89.5% of the total fish seed correlation of India.

Fishing gears used :-

The principal gears used in Ganga river system are dragnets, cast nets and bag nets.

Godavari River System:-

It originates in Doolai hills near Nasik in North Western Ghats. This river system is a part of East coast of pennensular river system, with a length of 1465 km covering the states like Maharastra, Andhrapradesh and Madhyapradesh. It has the primary tributaries like manjira, Wainganga; Subtributaries like paingunga and wardha and minor tributaries like maner mand sabari. It drains into Bay of Bengal. It has a total catchments area of over 315,980 sqkm

(Marine and Inland Fisheries)

Physico-Chemical characteristics:-

i) Temperature – 27.5 to 36.4°C

ii) PH – 7.2 to 8.3

iii) Do2 mg/L – 1.26 -18.2

iv) CO2 – 0.0 – 6.6 p pm

v) Bicarbonates – 45.8 -192-2ppm

(Marine and Inland Fisheries)

Krishna river system:-

The originates in Western Ghats region, south of Poona and finally drains into East coast, with an a length of 1401km covering the state like Maharastra, Karnataka and Andhrapradesh. It has the main tributaries like Bhima (Annual) and Tungabhadra (Perennial). This river system has an total catchments area of 2,33,229 sq km. The physico-chemical characteristics, fish fauna and the fishing gears used similar to the Godavari river system. In general, the physiographic and fish fauna resembles the Godavari river systems. The head waters support rich fishery when compared to mid-stretch, which is rocky and inaccessible. No information is available on its present fishery and catch statistics.

(Marine and Inland Fisheries)

Cauveri river System:-

This river system originates from Brahmagiri hills on western ghat, with an elevation of 1340 m extending to a length of 800 km. this river system covering the states the Karnataka and Tamil Nadu finally drains into Bay of Bengal in Thanjavur district of Tamil Nadu. It has the tributaries like Bhavani, Noyil and Amaravathi. This river system has an total catchment area of 4,70000 sq km. The water resources of the river are extensively exploited as numerous reservoirs, anicuts and barrages have been built on the river.

(Marine and Inland Fisheries)

Physico-Chemical characteristics:

i) Temperature – 26 to 30.9°C

ii) PH – 7.6 to 8.5

iii) Do2 mg/L – 1.2 6 -18

iv) CO2 – 0.0 – 6.6 ppm

v) Bicarbonates – 45.8 – 192-2ppm

(Marine and Inland Fisheries)

Narmada river system :-

This river system originates in Amarkantak hills of Madhya Pradesh, at an elevation of 1,057 m above the sea level. The length of the river is 1280 km, covering Madhyapradesh and Gujarat states and finally drains into gulf of Cambay in Gujarat. The effective catchments area of this river system is 94235 sq. km and 6330 sq. km of its all tributaries. This river system comprises of total 18 tributaries, of which 16 in Madhya Pradesh and 2 in Gujarat. This river system receives and annual rain fall of 12” – 115”.

(Marine and Inland Fisheries)

Fishery of Narmada river system:-

Narmada river harbors 84 fish species belonging to 23 genera. The contribution of carps in commercial fishery is of the order of 60.4%, followed by catfishes of 34.1 % and miscellaneous fishes of 5.5%. The carp fish groups are Tor tor; Labeo. frimbriatus; L.calabasu; L.bata; L.gonius; Cirrhinus. reba; Puntius. sarana etc, cat fish groups such as Mystus senghala ; M.aor ; M. cavasius; Wallago. Attu ; Clupisoma garua; Ompak bimaculatus and miscellaneous fish groups like Channa spp, Mastacembalus spp; Notopterus notopterus. Cast nets, gill nets and longlines are the fishing gears that are generally used in these waters.

(Marine and Inland Fisheries)

Tapti River System:-

This river system originates in Mount Vindhya of Satpura range at an elevation of 670 –100m above the sea level, with a total length of 720 km. This river system covers the states like Maharastra, Madhya Pradesh and Gujarat and finally drains into Arabian Sea at Dumas near Surat in Gujarat. The total catchments area of this river is 48,000 sq.km and annual rainfall is more or less similar to the Narmada river system.
Not much information of fish stock composition and fish yie ld is available. The main fisheries of this river system are Tor. tor; Mystus. seenghala; M.aor; Wallago attu; Labeo calabasu; L. fimbriatus; Puntius sarana; Cirrhinus mrigala; C. reba, Chupisorna garna; Channa spp; Mastacembalus. armatus. Cast nets, gillnets and long lines and also Mahajal is used as the fishing gear in these Factors influencing fish yield from rivers:-

(Marine and Inland Fisheries)

The intensity of fishing, nature of exploitation and species orientation are the characteristics of the artisan riverine fisheries and are governed by
i) Seasonality of riverine fishing activity
ii) Unstable catch composition
iii) Conflicting multiple use of r iver water
iv) Cultural stresses leading to nutrient lo ading and pollution.
v) Lack of understanding of the fluvial system and infirm data base.
vi) Fragmentary and out molded conservation measures lacking enforcement machinery.
vii) Inadequacy infrastructure and supporting services
viii) Affordability and playability and
ix) Socio- economic and socio-cultural determinant.