Fish Assemblages As Indicator Of Water Quality Biology Essay

Fish communities are more often used to measure quality or to supervise environmental alterations in estuarine environments. The estuarine environment, owing to its double Marine and fresh H2O features, supports a broad faunal diverseness ( Dreux, 1986 ; Mauvais and Guillaud, 1994 ; Bachelet et al. , 1997 ) and its biological productiveness is high. Fish gatherings are really varied, composed of true estuarine, amphihaline or euryhaline species ( Marchand and Elie, 1983 ; Elie et al. , 1990 ; Mauvais and Guillaud, 1994 ; Elliott and Dewailly, 1995 ; Methven et al. , 2001 ) .

Estuaries play a critical function in the operation of both marine and inland aquatic systems by supplying many Marine, migratory or estuarial species with basic demands for their life rhythm ( Potter et al. , 1986 ; Elie et al. , 1990 ) , such as cardinal home grounds for reproduction, eating, growing or physiological readying for migration ( Mc Dowall, 1988 ) . Due to their place within the drainage basin, these environments are among the most wedged by human activities ( Hostens and Hamerlynck, 1994 ; Maes, 2000 ; Cabral et al. , 2001 ) .

Length-weight relationship gives a great importance in piscary appraisal ( Garcia et al.,1989 ) . Therefore, the length and weight measurings with age informations can give information on the stock composing, age at adulthood, life span, mortality, growing and production ( King, 1996 ; Diaz et al. , 2000 ) . Other than that, the length-weight relationship besides utile in stabilising the systematic characters of the species every bit good as of import in direction and development of fish population ( Pervin & A ; Mortuza, 2008 ) . Besides, the length-weight relationship is important for the surveies on biological science, population and direction of species and their piscaries ( Le Cren, 1951 ; Shafi and Quddus, 1974 ) .

The length frequence informations fish will be analyzed utilizing particular plan bundle for length-based stock appraisal called FiSAT II ( FAO-ICLARM Stock Assessment Tools – Version 1.2.2 ) . This package will be developed for elaborate analysis of length frequence informations and other related analyses for illustration gimmick at age, size at age, choice and informations collected for tropical fish stock appraisal ( Gayanilo et al. , 1997 ) .

Water serves a battalion of utilizations. As the assorted utilizations have grown in diverseness, constrained by the more or less fixed measure available, important interaction of utilizations and reuses of H2O has besides developed. Water quality is a really wide term when used by some people and rather specific for others and is the complementary facet of H2O measure ( Biggar, 1979 ) . Chemically pure H2O seldom occurs in nature. Its content varies mostly from part to part, and is a contemplation of the local geographics and clime ( Hynes, 1970 ) . Harmonizing to Tanji Key to writers ‘ name: A. Suki ; M. Kemil ; T.P. Mok ( l979 ) , H2O is frequently referred to as a cosmopolitan dissolver and because of this solvent power, it tends to pick up drosss as it comes into contact with gases, liquids and solids.

In a underdeveloped state like Malaysia, rapid alterations are continually taking topographic point. These include population growing, urbanization, agricultural, excavation and logging activities, and industrialization.

These alterations bring about complex environmental jobs and the most of import natural resource that is affected is H2O ( Abu Bakar, 1985 ) . The development of land and natural resources, and the discharge of waste merchandises into the H2O organic structure are the chief H2O pollution beginnings in Malaysia particularly at Sungai Merbok in Kedah.

Aims of the survey

The aims of the survey are:

To depict the current fish gatherings in Sungai Merbok

To analyze the length-length and length-weight relationship of fish at Sungai Merbok

To analyze the monthly H2O qualities ( physical and chemical ) form in the Sungai Merbok

To analyze the effects and influences of the monthly H2O qualities fish species in the estuary Waterss of the Sungai Merbok.

two. Literature Review

Fish gatherings

Fish population can be analyzed utilizing length-weight relationship. Length and weight informations are utile standard consequences of fish sampling plans ( Morato et al. , 2001 ) . In fish, size is by and large more biologically relevant than age, chiefly because several ecological and physiological factors are more size-dependent than age-dependent. Consequently, variableness in size has of import deductions for diverse facets of piscaries scientific discipline and population kineticss ( Erzini, 1994 ) . Length-weight arrested developments have been used often to gauge weight from length because direct weight measurings can be time-consuming in the field ( Sinovcic et al. , 2004 ) .

One of the most normally used analyses of piscaries informations is length-weight relationship ( Mendes et al. , 2004 ) . The length-weight relationship can be done by mensurating the length and weight of fish taken at a peculiar clip because fish can continuously alter either in their length or weight. Length-weight relationships ( LWR ) provide basic information in piscaries biological science, being utile to find the weight of an single fish of known length or entire weight from length-frequency distribution, and to compare specific growing among different parts ( Froese, 1998 ; Koutrakis and Tsikliras, 2003 ) . This relationship was ab initio used to obtain information on the growing status of fish and to happen out whether the bodily growing was isometric or allometric ( Le Cren, 1951 ; Ricker, 1973 ) . Other than that, by utilizing length and weight informations, one can foretell the fish growing parametric quantities every bit good as predict the mortality rate which is utile in fish stock appraisal ( Samat et al. , 2008 ) .

Water Quality

The quality of H2O required to keep ecosystem wellness is mostly a map of natural background conditions. Some aquatic ecosystems are able to defy big alterations in H2O quality without any noticeable effects on ecosystem composing and map, whereas other ecosystems are sensitive to little alterations in the physical and chemical make-up of a organic structure of H2O and this can take to debasement of ecosystem services and loss of biological diverseness. The debasement of physical and chemical H2O quality due to human influences is frequently gradual, and elusive versions of aquatic ecosystems to these alterations may non ever be readily detected until a dramatic displacement in ecosystem status occurs. For illustration, in many shallow European lakes, the gradual enrichment of the surface H2O with works foods has resulted in displacement from systems that one time were dominated by frozen aquatic workss to systems that are now dominated by algae suspended in the H2O column ( Scheffer et al. 2001 ) . Regular monitoring of the biological, physical, and chemical constituents of aquatic ecosystems can function to observe utmost state of affairss in which the ability of an ecosystem to return to its normal province is stretched beyond its bound.

Typically, H2O quality is determined by comparing the physical and chemical features of a H2O sample with H2O quality guidelines or criterions. Drinking H2O quality guidelines and criterions are designed to enable the proviso of clean and safe H2O for human ingestion, thereby protecting human wellness. These are normally based on scientifically assessed acceptable degrees of toxicity to either worlds or aquatic beings. The scientific and regulative research community usage to place natural background conditions for chemicals that are non toxic to worlds or animate beings and to utilize these as guidelines for the protection of aquatic life ( Robertson et al. , 2006 ; Dodds and Oakes, 2004 ; Wickham et al. , 2005 ) . Other guidelines, such as those designed to guarantee equal quality for recreational, agricultural or industrial activities, set out bounds for the physical, chemical, and biological composing of H2O needed to safely set about different activities.

Methodology

Fishing Operation and Sampling locations

This research is located at the estuary of Sungai Merbok in the territory of Kuala Muda in Kedah It hence has the advantage of being sheltered from the strong air current and moving ridges. It is easy accessible from major towns like Sungai Petani, Alor Star and Butterworth. Furthermore, since it is situated near Tanjung Dawai.

By and large, the fishermen in Merbok and Kuala Muda applied the artisanal piscary. The information about the fishing operation in these countries will be cod by questioning the fishermen. Fishermans gave the needed information about fishing vass and boats, angling cogwheels and fishing operation. The information will be cod and noted by utilizing the signifier in a tabular array. Majority of fishermen in Kuala Muda use the trammel cyberspace or ‘pukat tiga lapis ‘ to catch the fish. Trammel cyberspaces are monofilament and consist of three bed of mesh. The outer mesh size will be 10.2 centimeter and interior mesh size will be 3.8 centimeter. The map of three beds will be to ‘secure ‘ the fish from get awaying and angle will mire. The net length will be 120 metres and net breadth will be 3-4 metres. This net floats vertically on the headrope and weighted on the groundrope. Trammel cyberspaces are most common as stationary cogwheel, but they can besides be used floating. The fish entangle themselves in a pocket of little mesh webbing between the two beds and big meshed walls. Afterwards, the trammel cyberspaces are hauled back to the surface for pull outing the miring fish from the netting.The fishermen in Merbok normally used barrier net or ‘pukat kering ‘ to catch the fish. The barrier cyberspace will be set up during low tide and prefer lowest tide twenty-four hours and dark operation. During high tide, fishermen use boat by drawing headline above H2O degree and procure the net to the poles. The gimmicks will be collected during low tide.

Prior to length, weight and other measurings, the fishes will be taken out from the deep-freeze and allowed to dissolve. The entire length ( TL ) of each fish will be taken from tip of neb to longest beam of caudal five. In other words, entire length is the maximal length of the fish. Then, standard length ( SL ) will be measured from the neb to the terminal of vertebral column. Fork length ( FL ) measured from the tip of the neb to the terminal of the in-between caudal five beams. The entire length, standard length and fork length measured in centimetres utilizing a mensurating board. Last, the organic structure weight ( BW ) in gm will be measured to the nearest 0.1 gm utilizing electronic weighing balance.

Length-Weight Relationships

The length-weight relationship will be determined by utilizing the information on the measuring of length and weight of Arius argyropleuron. The graph plotted by excel format ( XY spread ) with entire length ( TL ) on x-axis and organic structure weight ( BW ) on y-axis. The length-weight relationship can be expressed by utilizing equation:

W = aluminum B ( Le Cren, 1951 ; King, 1995 ; Froese, 2006 )

Where W = weight of the samples in gms ( g ) ,

L = length of the sample in centimetres ( centimeter ) ,

a = invariable ( intercept )

B = invariable ( incline of arrested development line )

The value of a and B may alter with age, sex, seasons and location ( Froese, 2006 ) . In piscaries pattern, cognition of length-weight relationship is really utile in fish stock appraisal and for piscaries direction ( Sparre and Venema, 1992 ) . The above equation can be transformed into additive signifier by utilizing equation:

ln W = ln a + B ln L ( Arshad et al. , 2008 )

All informations on entire length ( TL ) and organic structure weight ( BW ) transformed into ln TL and ln BW. Then the graph plotted with ln TL on x-axis and ln BW on y-axis in order to acquire the additive graph signifier alternatively of exponential signifier.

Water Qualities Sampling and Analysis

Water quality parametric quantities ( temperature, salt, turbidness, dissolved O, conduction, pH and Total suspended solid [ TSS ] , chlorophyll-a, biological O demand [ BOD ] , phosphate, nitrate and ammonium hydroxide ) of saltwater around the sampling sites will be cod and measured for both surface and bottom H2O. Water qualities information is obtained one time a month with two replicate at every station during the sampling of Portuguese man-of-war to let the finding of the exogenic environmental factors consequence on the monthly distribution and copiousness of jellyfish species in the estuary of the Sungai Merbok. Measurements of salt, dissolved O, pH, conduction and temperature are recorded unmoved. Other parametric quantities are analysed in the research lab from the H2O samples collected.

Table 1 List of equipments used for H2O qualities measurings.

No

Parameters

Measurements ‘ equipments/ methods

Unit of measurement

1

Temperature

YSI 85 DO-SCT metre

A°C

2

Salt

ppt

3

Conduction

mS/cm

4

Dissolved Oxygen

mg/L

5

pH

6

Turbidity

Secchi Disc

meter

7

Entire suspended solid

Standard manual method, APHA ( 1995 )

mg/L

8

Chlorophyll-a degree

Spectrophotometer

mg/L

9

Biological O demand

5- Days BOD Test, APHA ( 1995 )

mg/L

10

Phosphate, PO43-

Method by Strickland & A ; Parsond ( 1972 )

mg/L

11

Nitrate, NO3-

12

Nitrite, NO2-

13

Ammonia, NH3

Speciess Designations

Speciess Checklist

3 months Specimen Sampling

Water Qualities Sampling

Field Measurements

Length

Weight

Composition

Length-weight relationship

In-situ analysis

Phosphate

Ammonia

Nitrite

Nitrate

Toxic shock

Human body

pH

Temperature

Salt

Conduction

Dissolved Oxygen

Turbidity

Sites Survey/ verifier samples aggregation

Ex-situ analysis

Sampling Flow Chart

Gantt chart

Year 1

No.

Activities

Year 1

Joule

Joule

Oxygen

Second

Oxygen

Nitrogen

Calciferol

Joule

F

Meter

A

Meter

1.

Site survey/ voucher samples aggregation and saving

Ten

Ten

Ten

2.

Speciess Identification

Ten

Ten

Ten

Ten

Ten

Ten

3.

Speciess Checklist

Ten

Ten

Ten

Ten

Ten

Ten

4.

Field sampling and measurings

Ten

Ten

Ten

Ten

Ten

Ten

Ten

Ten

Ten

Ten

Ten

Ten

5.

Fish gatherings roll uping informations, Water qualities trying & A ; research lab analysis

Ten

Ten

Ten

Ten

Ten

Ten

Ten

Ten

Ten

Ten

Ten

Ten

6.

Field data & A ; consequence analysis

Ten

Ten

Ten

Ten

Ten

Ten

Ten

Ten

Ten

Ten

7.

Progress study composing

Ten

Ten

Ten

Ten

Year 2

No.

Activities

Year 2

Joule

Joule

Oxygen

Second

Oxygen

Nitrogen

Calciferol

Joule

F

Meter

A

Meter

1.

Field sampling and measurings

Ten

Ten

2.

Fish gatherings roll uping informations, Water qualities trying & A ; research lab analysis

Ten

Ten

3.

Field ‘s Data and consequence analysis

Ten

Ten

Ten

Ten

Ten

Ten

Ten

4.

Progress study composing

Ten

Ten

Ten

5.

Concluding thesis authorship

Ten

Ten

Ten

Ten

Ten

Ten

Ten

Ten

Ten

6.

Publication ( Journal & A ; presentation )

Ten