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India is the second-highest contributor to the post-2000 global greening. However, with satellite data, here we show that this 18.51% increase in Leaf Area Index (LAI) during 2001–2019 fails to translate into increased carbon uptake due to warming constraints. Our analysis further shows 6.19% decrease in Net Primary Productivity (NPP) during 2001–2019 over the temporally consistent forests in India despite 6.75% increase in LAI. We identify hotspots of statistically significant decreasing trends in NPP over the key forested regions of Northeast India, Peninsular India, and the Western Ghats. Together, these areas contribute to more than 31% of the NPP of India (1274.8 TgC.year−1). These three regions are also the warming hotspots in India. Granger Causality analysis confirms that temperature causes the changes in net-photosynthesis of vegetation. Decreasing photosynthesis and stable respiration, above a threshold temperature, over these regions, as seen in observations, are the key reasons behind the declining NPP. Our analysis shows that warming has already started affecting carbon uptake in Indian forests and calls for improved climate resilient forest management practices in a warming world. [ABSTRACT FROM AUTHOR]

The present study describes a new dataset that estimates seasonally integrated agricultural gross primary productivity (GPP). Several models are being used to estimate GPP using remote sensing (RS) for regional and global studies. Using biophysical and climatic variables (MODIS, SBSS, ECWMF reanalysis etc.) and validated by crop statistics, the present study provides a new dataset of agricultural GPP for monsoon and winter seasons in India for two decades (2001–2019). This dataset (GPPCY-IN) is based on the light use efficiency (LUE) principle and applied a dynamic LUE for each year and season to capture the seasonal variations more efficiently. An additional dataset (NGPPCY-IN) is also derived from crop production statistics and RS GPP to translate district-level statistics at the pixel level. Along with validation with crop statistics, the derived dataset was also compared with in situ GPP estimations. This dataset will be useful for many applications and has been created for estimating integrated yield loss by taking GPP as a proxy compared to resource and time-consuming field-based methods for crop insurance. Measurement(s) gross primary productivity Technology Type(s) remote sensing Factor Type(s) vegetation, radiation, water Sample Characteristic - Organism vegetation Sample Characteristic - Location India [ABSTRACT FROM AUTHOR]

The present study aims to estimate the spatio-temporal variability of gross primary productivity (GPP) in moist and dry deciduous plant functional types (PFTs) of northwest Himalayan foothills of India using remote sensing-based Temperature-Greenness (TG) model and to study the response of GPP to environmental variables. TG model was implemented in Google Earth Engine platform using Moderate Resolution Imaging Spectroradiometer enhanced vegetation index (MOD13A2) and land surface temperature (MOD11A2) from 2001 to 2018. The mean monthly GPP ranged from 1.80 to 18.57 gCm−2day−1 in moist deciduous and from 0.20 to 12.06 gCm−2day−1 in dry deciduous PFTs. On site-scale validation with eddy covariance flux tower GPP, the modelled GPP showed R2=0.79 for moist deciduous and R2=0.77 for dry deciduous PFT. Leaf area index showed the highest correlation with the predicted GPP (r = 0.74 for moist and 0.83 for dry deciduous PFTs). The study revealed that TG model could predict the long-term forest GPP with minimum in-situ inputs. [ABSTRACT FROM AUTHOR]

Benthic macroinvertebrates play important ecosystem roles in the cycling and outflow of nutrients. The benthos transforms organic detritus from sedimentary storage into dissolved nutrients that can be mixed into overlying waters and used by rooted plants (macrophytes) and algae (phytoplankton) to enhance primary productivity. This study examined the distribution pattern of benthic macroinvertebrates in a lesser Himalayan foothill stream from the headwaters (2,200m) to mouth (375m). Five stations (S1 to S5) were established along the 43-km course of the stream. Samples were collected at bi-monthly intervals from January to December 2009. The total density of the benthic macroinvertebrate community increased with decreasing altitude and differed significantly among stations. Dominant orders were Diptera at S1 (Simulidae, 27%) & S5 (Chironomidae 24%), Trichoptera at S2 (Limnephilidae 16%) & S3 (Hydropsychidae 9.9%), and Ephemeroptera (Heptageniidae 9.2%) at S4. Principal component analysis revealed that the characteristic taxa were Simulidae at S1, Limnephildae at S2, Hydropsychiidae, Rhyacophilidae, Tipulidae, Perlodidae, Dryopidae & Notonectidae at S3, Heptageniidae at S4, and Chironomidae, Siphlonuridae, & Agrionidae at S5. Cluster analysis showed one large cluster comprising S1 and S2 as sub-groups with resemblance to S3-S4, and S5 as an outlier. The similarity between the stations S3-S4 was attributed to similar landuse pattern (agriculture) and stream order (II Order), while S1 and S2 were slightly similar due to partial similar forest type (oak forest at S1, pine-oak forest at S2) and stream order. At S5, however, the considerable change in forest type (mixed forest) land-use and stream order (III Order) caused S5 as an outlier in cluster. The variations in the abundant and characteristics taxon at different stations were attributed to change in substratum and land-use patterns. [ABSTRACT FROM AUTHOR]

Net Primary Productivity (NPP) is a significant biophysical vegetation variable to understand the spatio-temporal distribution of carbon and source-sink nature of the ecosystem. This study was carried out in a forest plantation area and aimed to (i) estimate the spatio-temporal patterns of NPP during 2009 and 2010 using Carnegie-Ames-Stanford Approach [CASA] model and (ii) study the effects of climate variables on the NPP using generalized linear modelling (GLM) approach. The total annual NPP varied from 157.21 to 1030.89 gC m−2 yr−1 for the year 2009 and from 154.36 to 1124.85 g C m−2 yr−1 for the year 2010. The annual NPP was assessed across four major plantation types, where maximum NPP gain (106 and 139 g C m−2 yr−1 ) in October was noticed in teak (Tectona grandis) and minimum (77 and 109 g C m−2 yr−1 ) in eucalyptus (Eucalyptus hybrid) during 2009 and 2010.The validation, using field-estimated NPP, showed under-estimation of modelled NPP, with maximum MAPE of 34% for eucalyptus and minimum of 13% for teak. The dominant influence of precipitation on the NPP was revealed by GLM explaining more than 20% of variation. CASA model efficiently estimated the annual NPP of plantations. The accuracy could be improved further with inclusion of higher resolution data. [ABSTRACT FROM AUTHOR]

The realization of the potential importance of phosphorus (P) as a limiting nutrient in marine ecosystem is increasing globally. Hence, the contribution of biotic variables in mobilizing this nutrient would be relevant especially in productive coastal waters. As alkaline phosphatase activity (APA) indicates the status of P for primary production in aquatic environments, we asked the following question: is the level of APA indicative of P sufficiency or deficiency in coastal waters, especially, where upwelling is a regular phenomenon? Therefore, we have examined the total APA, chlorophyll a along with phosphatase producing bacteria (PPB) and related environmental parameters from nearshore to offshore in coastal waters off Trivandrum and Kochi regions differently affected by upwelling during the onset of monsoon. Off Trivandrum, APA in the offshore waters of 5-m layer at 2.23 μM P h − 1 was > 4 times higher than nearshore. Thus, low APA could be indicative of P sufficiency in coastal waters and higher activity suggestive of deficiency in offshore waters off Trivandrum. In contrast, there was less difference in APA between near and offshore surface waters off Kochi. Our results show that the regions differently affected by upwelling respond differently according to ambient P concentration, distance from shore or depth of water. These observations could apparently be applicable to other coastal systems as well, where gradients in upwelling and phosphate runoff have been noticed. Further studies on other transects would throw more light on the extent and direction of the relationship between APA and ambient P concentration. Such studies would help in understanding the level of control of this nutrient on the productivity of coastal waters. [ABSTRACT FROM AUTHOR]

Abstract: Chilika, the second largest lagoon of the world was studied for 2 years on monthly basis to understand the dissolved inorganic carbon (DIC) dynamics through mass balance approach. The study revealed that during the low flow period the lagoon is net autotrophic (Net ecosystem production (NEP)=33Mgd−1) resulting in a sink of DIC whereas remains net heterotrophic during the high flow period (NEP=−3099Mgd−1). DIC concentration significantly varied with respect to seasons as well as sectors owing to fresh water discharge and biological activity of both pelagic and benthic communities. Sectoral mixing model showed negative residuals (sink of DIC) in all sectors during low flow, attributable to primary production (PP) as evidenced by strong correlation with residuals (r=−0.51, p<0.05). During high flow, DIC residuals of the entire lagoon (except southern sector) were positive (source of DIC) possibly due to bacterial mineralization as evidenced by δ 13 C DIC isotopic signature. The estimated net community production (NCP) in pelagic compartment was 14mgCm−2 d−1 during the low flow period. and −148mgCm−2 d−1 during high flow indicated dominating community respiration. The lagoon sediment acted as a net source of DIC throughout the study period. [Copyright &y& Elsevier]

The present study was carried out to make an ecological evaluation of physico -- chemical characteristics in Barna reservoir during various seasons. Barna reservoir is a tropical reservoir which is constructed on river Barna, a tributary of river Narmada in central India. For evaluation of seasonal changes in water quality of Barna reservoir water samples were collected on monthly basis for a certain period from January 2009 to December 2009 and a total of 19 parameters were analyzed according to standard methods. The results revealed that the ecology of Barna reservoir in different seasons showed dynamism in physico -- chemical parameters which could be due to various factors like input of fertilizers, weathering of rocks, meteorological phenomenon and other activities in catchment area. [ABSTRACT FROM AUTHOR]

Using satellite observations of Normalized Difference Vegetation Index together with climate data from other sources in a terrestrial biosphere model, inter-annual variability of Net Primary Productivity (NPP) over India during 1981-2006 was studied. It is revealed that the variability is large over mixed shrub and grassland (MGL), moderate over cropland and small over the forest regions. Inter-annual variability of NPP exhibits strong positive coherence with the variability of precipitation, and weak coherence with the variability of temperature and solar radiation. Estimated linear growth rate of annual NPP is 0.005 Pg C Yr−2 which is equivalent to 8.5% over the country during past 25 years. This increase is primarily due to the enhancement of productivity over agricultural lands in the country. NPP has increased over most parts of the country during the early 15-year period (1981-1995) resulting in a 10% growth rate of national NPP budget. On the other hand, the NPP growth rate has been reduced to 2.5% during later 15 years period (1991-2005) owing to large decline of NPP over the Indo-Gangetic plains. Climate had a strong control on NPP growth rate during both the periods. Copyright © 2012 Royal Meteorological Society [ABSTRACT FROM AUTHOR]

Net photosynthesis rate (PN) has an important role in controlling the ecosystem primary production and it is important to understand the relationships between PN and other physiological and environmental variables to improve and develop models for predicting plant growth and productivity. Here we study utility of ground-based hyperspectral measurements in estimating net photosynthesis during the growth cycle of rice. Ground-based hyperspectral reflectance and micrometeorological data (PN, chlorophyll concentration index (CCI), photosynthetically active radiation (PAR)) were collected from a rice field on three dates in the kharif season at Meerut, Uttar Pradesh, India. Green chlorophyll index (CIg) showed a positive and statistically significant relationship with CCI (R2 = 0.64). Use of single index showed poor fit with PN. The model based on a combination of two variables (vegetation index (VI) × PAR) however proved better in explaining the variance of PN. Among the VI-based combinations comprising three variables which depend on the Monteith light-use efficiency (LUE) concept, models consisting of either CIg or CCI as one variable appeared to be the best in predicting PN with R2 of nearly 0.6. The study concludes that a single index is insufficient to account for factors controlling variation in PN estimation whereas Monteith logic-based combinations have shown its potential for PN estimation by incorporating the chlorophyll based and other vegetation indices as the proxy of LUE and fAPAR (fraction of absorbed photosynthetically active radiation) respectively. [ABSTRACT FROM AUTHOR]

Present study aims at estimation and validation of net primary productivity (NPP) using production efficiency model (PEM), and its possible relationship with tree diversity. The PEM estimates NPP, based on light use efficiency (LUE) and intercepted photosynthetically active radiation (IPAR). Weighted average LUE varied between 0.02 gC/μmol/m of PAR (Mixed forest (miscellaneous)) to 0.08 gC/μmol/m of PAR ( Acacia forest), in growing phase (GP), and 0.0008 gC/μmol/m of PAR ( Boswellia mixed forest) to 0.023 gC/μmol/m of PAR ( Acacia forest) during the senescent phase (SP). The average weighted LUE for tropical dry and Moist deciduous forest (MDF) in GP were 0.05 gC/μmol/m of PAR and 0.03 gC/μmol/m of PAR, respectively. The average IPAR for different forest types was 2079.58 μmol/m/s during GP and 1510.58 μmol/m/s during SP. The PEM based NPP varied between 0.58-275.78 gC/m/year during GP and 0.43-74.34 gC/m/year during SP. The PEM based NPP and conventional (ground based) NPP were related with R of 0.55. The tree diversity and NPP relationship was observed with R of 0.55 at the level of both plot and forest types. [ABSTRACT FROM AUTHOR]

The primary productivity of the river River Kharashrota (Orissa) has been analysed both spatially and seasonally. The maximum GPP was noted during summer season and minimum in rainy season at all the six stations. The annual average GPP varied from 0.075±0.009 gC.m-3.h-1 to 0.938±0.103 gC.m-3.h-1.The NPP value varied from 0.012±0.001 gC.m-3.h-1 to 0.832±0.081 gC.m-3.h-1 and exhibited an increasing trend from the month of September to February. The community respiration (CR) ranged from 0.026±0.002 gC.m-3.h-1 to 0.496±0.043 gC.m-3.h-1 and exhibited a systematic seasonal pattern with maximum and minimum value during summer and winter respectively at all the stations. The correlation of NPP, GPP and CR with some of the physico-chemical parameters has also been established. [ABSTRACT FROM AUTHOR]

The article presents a study which explored the density changes of waterbird species from Santragachi Lake in India. Limnological investigations were carried out in relation to the expected impact of migratory waterbird use. Results indicate negative associations of major nutrients with both higher avian densities and gross primary productivity (GPP).

In the present study, the Carnegie-Ames-Stanford Approach (CASA), a terrestrial biosphere model, has been used to investigate spatiotemporal pattern of net primary productivity (NPP) during 2003 over the Indian subcontinent. The model drivers at 2-min spatial resolution were derived from National Oceanic and Atmospheric Administration advanced very high resolution radiometer normalized difference vegetation index, weather inputs, and soil and land cover maps. The annual NPP was estimated to be 1.57 Pg C (at the rate of 544 g C m), of which 56% contributed by croplands (with 53% of geographic area of the country (GAC)), 18.5% by broadleaf deciduous forest (15% of GAC), 10% by broadleaf evergreen forest (5% of GAC), and 8% by mixed shrub and grassland (19% of GAC). There is very good agreement between the modeled NPP and ground-based cropland NPP estimates over the western India ( R = 0.54; p = 0.05). The comparison of CASA-based annual NPP estimates with the similar products from other operational algorithms such as C-fix and Moderate Resolution Imaging Spectroradiometer (MODIS) indicate that high agreement exists between the CASA and MODIS products over all land covers of the country, while agreement between CASA and C-Fix products is relatively low over the region dominated by agriculture and grassland, and the agreement is very low over the forest land. Sensitivity analysis suggest that the difference could be due to inclusion of variable light use efficiency (LUE) across different land cover types and environment stress scalars as downregulator of NPP in the present CASA model study. Sensitivity analysis further shows that the CASA model can overestimate the NPP by 50% of the national budget in absence of downregulators and underestimate the NPP by 27% of the national budget by the use of constant LUE (0.39 gC MJ) across different vegetation cover types. [ABSTRACT FROM AUTHOR]

Copyright of Tropical Ecology is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Extensive observations during the late Southwest Monsoon of 2004 over the Indian and Omani shelves, and along an east-west transect reveal a mosaic of biogeochemical provinces including an unexpected high-nutrient, low-chlorophyll condition off the southern Omani coast. This feature, coupled with other characteristics of the system, suggest a close similarity between the Omani upwelling system and the Peruvian and California upwelling systems, where primary production (PP) is limited by iron. An intensification of upwelling, reported to have been caused by the decline in the winter/ spring Eurasian snow cover since 1997, is not supported by in situ hydrographic and chlorophyll measurements as well as a reanalysis of ocean colour data extending to 2009. Iron limitation of PP may complicate simple relationship between upwelling and PP assumed by previous workers, and contribute to the anomalous offshore occurrence of the most severe oxygen (O2) depletion in the region. Over the Indian shelf, affected by very shallow O2-deficient zone, high PP is restricted to a thin, oxygenated surface layer probably due to unsuitability of the O2-depleted environment for the growth of oxygenic photosynthesizers. [ABSTRACT FROM AUTHOR]

Abstract: In-situ measurements of benthic fluxes of oxygen and nutrients were made in the subtidal region of the Mandovi estuary during premonsoon and monsoon seasons to understand the role of sediment–water exchange processes in the estuarine ecosystem. The Mandovi estuary is a shallow, highly dynamic, macrotidal estuary which experiences marine condition in the premonsoon season and nearly fresh water condition in the monsoon season. The benthic flux of nutrients exhibited strong seasonality, being higher in the premonsoon compared to the monsoon season which explains the higher ecosystem productivity in the dry season in spite of negligible riverine nutrient input. NH4 + was the major form of released N comprising 70–100% of DIN flux. The benthic respiration rate varied from −98.91 to −35.13mmolm−2 d−1, NH4 + flux from 5.15 to 0.836mmolm−2 d−1, NO3 − +NO2 − from 0.06 to −1.06mmolm−2 d−1, DIP from 0.12 to 0.23mmolm−2 d−1 and SiO4 4− from 5.78 to 0.41mmolm−2 d−1 between premonsoon to monsoon period. The estuarine sediment acted as a net source of DIN in the premonsoon season, but changed to a net sink in the monsoon season. Variation in salinity seemed to control NH4 + flux considerably. Macrofaunal activities, especially bioturbation, enhanced the fluxes 2–25 times. The estuarine sediment was observed to be a huge reservoir of NH4 +, PO4 3− and SiO4 4− and acted as a net sink of combined N because of the high rate of benthic denitrification as it could remove 22% of riverine DIN influx thereby protecting the eco system from eutrophication and consequent degradation. The estuarine sediment was responsible for ∼30–50% of the total community respiration in the estuary. The benthic supply of DIN, PO4 3− and SiO4 4− can potentially meet 49%, 25% and 55% of algal N, P and Si demand, respectively, in the estuary. Based on these observations we hypothesize that it is mainly benthic NH4 + efflux that sustains high estuarine productivity in the NO3 − depleted dry season. [Copyright &y& Elsevier]

In view of being an important process in ecosystems and of great significance to ecological studies, net primary productivity, together with accumulation of plant dry matter and its transfer dynamics, was studied in two grasslands occurring at elevations of 1600 m (low elevation grassland) and 1950 m above mean sea level (high elevation grassland). Thirty eight species occurred at the low elevation grassland and 11 species were recorded at the high elevation grassland. Maximum aboveground live plant biomass in low elevation grassland was 422.00 g m-2 and the same in high elevation grassland was 2189.30 g m-2. Peak values of standing dead material in the two grasslands were 558.6 g m-2 and 2377.2 g m-2, respectively. The litter mass in the low elevation grassland ranged from a low of 156 g m-2 to a high of 1111 g m-2 while as the corresponding Values in the high elvation grassland were 840 g m-2 and 1590 g m-2, respectively. Belowground drymass was also higher (5016.50 g m-2 ) in high elevation grassland compared to low elevation grassland wherein peak belowground drymass was 1691.50 g m-2. Aboveground Net Productivity (ANP), Belowground Net productivity (BNP) and Total Net Productivity (TNP) values in the low elevation grassland were 1467.76 g m-2y-1, 1940.00 g m-2y-1, and 3408.21 g m-2y-1, respectively. The corresponding values in the high elevation grassland were 3088.69, 6072.50 and 9161.19 g m-2y-1. Of the total TNP, 43% and 34% were transferred to ANP in low- and high elevation grasslands, respectively. About 57% and 67% of TNP was transferred to BNP in the two grasslands. The turnover rates of aboveground live biomass and belowground biomass in the low elevation grassland were 3.48 and 1.58, respectively and the corresponding values in the high elevation grassland were 1.41. and 1.21. [ABSTRACT FROM AUTHOR]

Copyright of Tropical Ecology is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This Study describes biomass and net primary productivity of a grazingland in a montane forest of Garhwal Himalaya. Four sites were selected for the study, which were open, and located on south and north aspects, i.e., south upper slope (SUS), south lower slope (SLS), North upper slop (NUS) and north lower slope (NLS). All the sites had similar type of growth pattern representing peak biomass value in September ranging for 640.50 to 780.6 g m-2. Net aboveground and belowground production peaked in different, months. Site NUS was subjected to some biotic interference as cattle of shepherd and nomadic people visited it. ANP ranged form 664.7 to 853.2 g m-2 yr-1 and peaked in September on three sites. BNP was recorded highest in November and ranged from 858.2 to 1062.1 g m-2 yr-1 on all the sites. The sedges had highest contribution on three sites while the grasses were dominant on one site. Winter season was severe and long with food accumulation in belowground parts that is utilized in next growing season. [ABSTRACT FROM AUTHOR]

• Terai ecosystems in India are threatened by habitat loss and dry-season fires. • Fires are used to control woody species encroachment into grassland areas. • The ratio of grassland to woodland appears not determined by climate. • Using long-term satellite data, we found that non-climatic drivers influence fires. • Current fire management disproportionately affects roadside habitats. The Terai ecoregion of the Himalayan foothills is among the most fire-affected ecosystems in the Indian sub-continent. Although most of the Terai has already been lost to agriculture and urbanization, the few remaining native habitats are strictly protected due to their high biodiversity and ecological importance. The use of fires to maintain vegetation and wildlife habitat in these protected areas is an integral part of forest management. Although fires are initiated by forest managers or local people, their eventual spread and behaviour are not controlled. We hypothesize that distributions of fires are determined by several direct and indirect drivers like fuel load, fuel moisture content, presence of natural or artificial fire breaks, and climatic attributes of precipitation and temperature. Using the moderate-resolution (375m) satellite sensor-based data we studied the environmental influence on the spatial-temporal patterns of fire events over 18 years (2000-2018) in a 519 km2 protected area in northeastern India. The park has a mosaic of vegetation formations – including dry and swampy alluvial grassland, early successional woodland, and moist tropical forest. Despite high rainfall, there is an intense dry season that renders the herbaceous vegetation susceptible to fires. Using spatial and spatial-temporal Poisson regression models in a rigorous conditional autoregressive Bayesian framework, we found that net primary productivity (a proxy of vegetation type and fuel load), distance to roads (a measure of human influence), elevation (through its influence on floods and vegetation type), and river area extent (by determining the area under vegetation) had a significant influence on the spatial distributions of fires. The climatic signal on interannual variation in fires was weak, but dry season rainfall reduced fire incidence. The disproportionate distribution of fires adjacent to roads compared to the interior, and the repeated burning of some grassland patches need to be addressed in fire management. [ABSTRACT FROM AUTHOR]

Discusses the plant biomass, species diversity and net primary production in a high altitude grassland in Central Himalaya, India. Relative growth rate of live shoots; Increasing dominance of Danthonia cachemyriana with advancement of the growing season; Association between total dry matter disappearance and total net organic matter input.

The present study attempts to understand the seasonal and spatial variations in the physico-chemical (temperature, pH, salinity, dissolved oxygen, and nutrients) and productivity characteristics of the northern Arabian Sea off the Indian coast. Samples were collected from four different sites off the Veraval coast. The values of the physical and chemical variables were higher during the summer season, whereas nutrient concentrations were high during the winter season due to the maturity of intake nutrients during post-monsoon and winter convective mixing during the northeast monsoon. The dissolved oxygen (DO) concentration was strongly and positively correlated with the net primary productivity (NPP) and chlorophyll a (Chl-a) content to support productivity along the region. Dissimilarity in study variables was observed between the inshore and offshore locations. Principal component analysis revealed a strong relationship between nutrients and productivity variables (Chl-a and NPP). Nutrient levels were high at inshore sites, which can be attributed to the heavy nutrient load from land-based anthropogenic activities and impact due to natural processes like water mixing, sedimentation, and wave activities. Nutrients were strongly and positively correlated with the productivity variables, i.e., Chl-a and NPP. Chl-a positively correlated with NPP (r = 0.90), which indicates that it is a principle productivity pigment in the marine ecosystem. [ABSTRACT FROM AUTHOR]