Annual variation of primary production and chlorophyll-a of the inshore area ofTuticorin indicated

three peak periods. during March-April. June-July and September-October. The multipfe regression

analysis indicated significant levels of co-relation by chlorophyll-a and nitrates with primary production.

Among nutrients only nitrate and phosphate have influence on primary production while nitrite and silicate

have insignificant role. The usefulness of chlorophyll-a in relation to the primary production rates as a

measure of.the standing crop of phytoplankton and the role of nutrients in the organic production of the

inshore area of Tuticorin are also briefly discusse

Gopinathan, C P

Kasim, H M

Rajagopalan, M S

Rodrigo, Joseph Xavier

209-212Annual variation of primary production and chlorophyll-alpha of the inshore area of Tuticorin indicated three peak periods, during March-April, June-July and September-October. The multiple regression analysis indicated significant levels of co-relation by chlorophyll-alpha and nitrates with primary production. Among nutrients only nitrate and phosphate have influence on primary production while nitrite and silicate have insignificant role. The usefulness of chlorophyll-alpha in relation to the primary production rates as a measure of the standing crop of phytoplankton and the role of nutrients in the organic production of the inshore area of Tuticorin are also briefly discussed

Rodrigo, J X

Kasim, H Mohamed

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Phytoplankton pigments in relation to primary production and nutrients in the inshore waters of Tuticorin, southeast coast of India

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Indian Journal of Marine Sciences Vol. 23. December 1994. pp. 209-212 Phytoplankton pigments in relation to primary production and nutrients in the inshore waters of Tuticorin, southeast coast of India C P Gopinathan, J X Rodrigo. H Mohamed Kasim & M S RajagopaJan Central Marine Fisheries Research Institute, P.B. No. 1603, Cochin-682 014. Kerala. India Received 23 September 1993. revised 8 September 1994 Annual variation of primary production and chlorophyll-a of the inshore area ofTuticorin indicated three peak periods. during March-April. June-July and September-October. The multipfe regression analysis indicated significant levels of co-relation by chlorophyll-a and nitrates with primary production. Among nutrients only nitrate and phosphate have influence on primary production while nitrite and silicate have insignificant role. The usefulness of chlorophyll-a in relation to the primary production rates as a measure of.the standing crop of phytoplankton and the role of nutrients in the organic production of the inshore area of Tuticorin are also briefly discussed. In recent years, considerable infonnation is available on primary productivity of Ihe coastal walers of Ihe Indian seas in general and the east coast in parti-cular l - ' , yet very little informationo., is avilable on the phytoplankton pigmenls of the coastal waters in the Gulf ofMannar. In this study, an attempt has been made to examine the phytoplankton pigments in relation to the primary production and nutrients of the surface waters of the inshore area of Tuticorin, during 1985-88. Materials and Methods Fortnightly water samples were collected on board the research vessels, Cadalmin-IVand M .L. Chippy. Surface water was collected between 0730-0900 hrs from the inshore area. Although 2 stations in the inshore area (Fig. I) were sampled, only pooled values for these stations are presented. Primary production' was measured on board the research vessel in simulated in .situ conditions. Winkler's method was employed for the estimation of oxygen and the same converted for carbon equivalent using a PQ of 1.25 for obtaining the gross production. Estimation of chlorophylls and phaeo-pigments of the surface water was made by filtering one litre of seawater using Millipore HA filters and the same dissolved in 90% acetone and the optical densities were measured using a spectrophotometer (ECL-GS 5700). Chlorophylls and phaeo-pigment concen-trations were calculated and nutrients such as nitrite, nitrate, phosphate and silicate were analysed by standard procedures·. However, data related to the nutrients for the period 1985-86 are not available. Multiple regression analysis was made to study the co-relation of these pigments and the nutrients of the seawater with the rates of primary production. Results and Discussion Primary production- The rates of gross primary production (Fig. 2A) shows wide range of fluctua-tions in different months. Three peak periods have been noticed; the primary one during March-April, eSt. I .51.2 Fig. I- Sampling stations in the inshore wa ters of Tuticorin 210 INDIAN J. MAR. SCI.. VOL. 23. DECEMBER t994 with high magnitude and the second during June-July and the third during September-October which werc of less magnitude. Production was low during November-Janua ry. The average prima ry production for the inshore waters was estimated as 350 mgc. m- -'.d - I with relatively higher "alues observed during Apri l '88 (1600 mgc. m - J d - I) and very low values of 114 mgc. m - -'.d- I during NO"ember '85 . Ch/oropiIrlls--Chloro phyll-a (Fig. 28) ranged from 1.2 to 11. 8 mg.m - 3 Chlorophyll-a values showed di stinct seasonal variations and a close direct 01 5 :;: U 4 .... . S?' 3 c. " 2 v 0 '" 1l. 06 0 ' .... 004 .0 1 '" 0 ·2 u o :l[ ;;;- t ~ 'eo 1·0 05 6 ~ 0 '" :4n .01 t . I · , E 0 6 ::c cj. 0 ·2 relationship with the primary production. Three peak periods ha ve been noticed. during March-April. June-July and September-October. simi lar to the peak periods of primary production. Chlorophyll-h (Fig. 2C) showed distinct seasonal variations similar to chi-a. Chlorophyll-b ranged from 0.1 to 1.8 mg.m - 3 during the entire period of obsc rnitions. High "alues of chi-I> were noted ir. April. J une-J uly. September and December-January months. Ch lorophyll-I> values were found to be always less than the values of chi-a. During September '86. an exceptionally high values of ehl-b G F E D c ;i '11 ' _; IOC,r6~~ ~':". ! 200 A 0: E 800 E U 400 ~ ! 0 LAL.JM~J-'-J-A~S'-'O--'N:::D:"":'-J -F~M~A-'-M-'-J-J~A'-'S~0-N=o9J'-'F~M--'.~-M'"-J'-'J'-'A~S-'-0-N'-'DYJ~F~M 1985- 86 198(;-87 1987 - 88 Fig. ~- Sl'a~l)nal \ ariations of\'<l rious phytoplankton ri~men ls in rdation to primary prwu(,lion and inter-relationship at th(' surface .,\ 'It~rs in !h~ inshore arca l) f Tuticnri n GOPINATHAN et aL: PHYTO,"lANKTON PIGMENTS 211 was noted which coincided with the third peak of primary production. Figure 2D shows the values of chl-c for the study period. The chl-c values ranged from 0.02 to 1.2 mg.m - 3. The values are exceptionally low when compared to the values estimated from the west coast of India1o.". Similar to chl-b, chl-c showed no distinct variations, but January-February, April, June-July and September months showed moderate values of chi-c. Phaeo-pigments-Phaeo-pigments (Fig. 2E) show close resemblance to chi-a. Three seasonal peaks have been observed for phaeo-pigments, and ranged from 0.5 to 11:2 mg.m- 3 . Unusually high values were noted during June '85, July '86 and April '87. The values of phaeo-pigments reveaJed the dominance of dead photosynthetic pigments in the inshore area of Tuticorin. The inter-relationship of pigments in the surface waters of the inshore area, expressed in terms of ratios, chl-b/a and phaeo-pigments/chl-a are given in Fig. 2F, O. It can be seen that the ratio chl-b/a was considerably lower, ranged from 0.01 to.0.66 . while the ratio between phaeo-pigments/chl-a was slightly higher, ranged from 0,06 to 5.2 in some months. These ratios of different components of chlorophylls give an insight into th.e photo-adaptability, physiological and degradation state of communities. The high ratios of phaeo-pig-ments/chl-a suggest the abundance of detritus and predominance of degraded chlorophylls in the inshore waters. Nutrients- Monthly average values of inorganic nutrients such as nitrite, nitrate, phosphate and silicate for the period 1986-88 are represented in Fig. 3. Both nitrite and nitrate values (Fig. 3A, B) were found to increase during April-July and September-November periods, coinciding with the 2 peak periods of primary production. High rate of primary production and high values of chl-a and nitrates indicated a positive co-relation during the period of study. Phosphate variations are unimodal with 2 periods of abundance (Fig. 3C), during o c B A ~ bd ~ .. 1986-87 1987-88 Fig. J.-The monthly average values of nutrients at the surface waters of the inshore area March-June and August-December. During July-September and November '88 values are. low and coincided with the peak periods of primary production, sugesting higher utilization of inorganic phosphate by the phytoplankton. Values of silicate (Fig. 3D) showed less fluctuations as compared to other nutrients. Slalislica/I1IUl/Ysis- To examine the dominance of different pigments and nutrients on primary production, multiple regression analysis of these parameters was carried out by treating chi-a. -b. -c phaeo-Jiigmenis arid nitrite, nitrate, pho'sphate and silicate as the independent variables and primary production as the dependent variable. Though the coe-efficient of determination (R2) in all the treatments are not high enough, say above 0.8 to permit a confident speculation about cause and effect of the independent variables, the estimates on correlation coefficients, standard partial regression coefficient (SPRC), F ratio and t values indicated that among pigments chl-a had a significant role in the primary production in 1986-87 and 1987-88 and nitrate in 1986-87. The I test indicates that except chi-a, none of the pigments were significant for primary production during 1985-86 (P =' < 0.2) and 1987-S8(P = < 0.05) whereas in 1986-87,chl-band c also exhibited significant levels to a limited extent (P < 0.5 and P = < 0.04) along with chl-a (P = < 0.03). The treatment of nutrients indicate that the influence of different nutrients on primary production was in the order of nitrate (P = < 0.1), phosphate (P = < 0.25), silicate (P = < 0.4) and nitrite (P = < 0.5) during 1986-87. Multiple regression analysis proved that all phytoplankton pigments are not contributing substantially for the organic production of the surface waters. Among the pigments, chl-a ,had a significant role in the production rates while the dominance of phaeo-pigments indicated the abundance of non-photosynthetic pigments and -dead chlorophylls. Among nutrients, only nitrate and phosphate have influence on primary production while nitrite and silicate have insignificant role. Usefulness of chl-a in relati"n to primary production as a measure of the standing crop has been verified since a direct relationship exists between primary production and c;,bl-a for the inshore waters. Acknowledgement The authors are grateful to Dr P S B R James, Director, for his keen interst and encouragement. References I Nair P V R, Bull CMFRI. 22 (1970) 56. 212 INDIAN J. MAR SCI, VOL. 23, DECEMBER 1994 2 Nair P V R. Samuel S. Joseph K J & Balachandran V K. in Proceedings of the symposiwn on living res()Urces of lhe seas around India, Mar BioI Ass India (Spl Pubtil (1968) 184. 3 QasimSz, WellershawsS, Bbattathiri PM A &AbidiSAH, hoc Indian Acad Sci, 19 (1969) 51. 4 QasimSz, BhattathiriPMA&AbidiSAH,J ExpMar BioI £Col, 2 (1968) 87. 5 Radbaltrishna K, Devassy V P, Bhargava R M S & Bhattathiri PM A, Indion J Mar Sci, 7 (1978) 271. 6 Marichamy R, Gopinathan C P & Pon Siraimeetan, J Mar Bioi Ass India, 27 (1985) 128. 7 Gopinatban CP& RodrigoJ X,J Mar BioI Ass India, 33(1991) 33. 8 Gaarder T & Gran H H, Rap Proced Verb Cons Expl Mer , 42 (1927) 48. 9 Strickland J D H & Parsons T R, A practical handbook of seawateranaiysis, Bull No 161 (Fish Res Bd Canada, Ottawa) 1972, pp.311. 10 Qasim S Z & Reddy C V G, Bull Mar Sci, 17 (1967) 110. II Qasim S Z, Bhattathiri P M A & Devassy V P, Mar BioI, 12 (1972) 206. 

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Phytoplankton pigments in relation to primary production and nutrients in the inshore waters of Tuticorin, southeast coast of India

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