scholarly journals Simultaneous measurement of phytoplanktonic primary production, nutrient and light availability along a turbid, eutrophic UK east coast estuary (the Colne Estuary)

2002 ◽  
Vol 231 ◽  
pp. 1-12 ◽  
Author(s):  
E Kocum ◽  
GJC Underwood ◽  
DB Nedwell
Keyword(s):  
Primary Production ◽  
Simultaneous Measurement ◽  
East Coast ◽  
Light Availability ◽  
Colne Estuary

scholarly journals Light availability in the coastal ocean: impact on the distribution of benthic photosynthetic organisms and contribution to primary production

2006 ◽  
Vol 3 (4) ◽  
pp. 895-959 ◽  
Author(s):  
J.-P. Gattuso ◽  
B. Gentili ◽  
C. M. Duarte ◽  
J. A. Kleypas ◽  
J. J. Middelburg ◽  
...  
Keyword(s):  
Primary Production ◽  
Surface Area ◽  
Coastal Zone ◽  
Benthic Communities ◽  
Light Availability ◽  
Coastal Ocean ◽  
Shelf Area ◽  
Primary Producers ◽  
Benthic Primary Production ◽  
Photosynthetic Organisms

Abstract. One of the major features of the coastal zone is that part of its sea floor receives a significant amount of sunlight and can therefore sustain benthic primary production by seagrasses, macroalgae, microphytobenthos and corals. However, the contribution of benthic communities to the primary production of the global coastal ocean is not known, partly because the surface area where benthic primary production can proceed is poorly quantified. Here, we use a new analysis of satellite (SeaWiFS) data collected between 1998 and 2003 to estimate, for the first time at a nearly global scale, the irradiance reaching the bottom of the coastal ocean. The following cumulative functions provide the percentage of the surface of the coastal zone receiving an irradiance greater than Ez: PaNon-polar=28.80−16.69 log10(Ez)+0.84 log102(Ez)+0.83 log103(Ez) PaArctic=16.01−15.67 log10(Ez)+2.03 log102(Ez)+1.00 log103(Ez) Data on the constraint of light availability on the major benthic primary producers and net primary production are reviewed. Some photosynthetic organisms can grow deeper than the nominal bottom limit of the coastal ocean (200 m). The minimum irradiance required varies from 0.4 to 5.1 mol photons m−2 d−1 depending on the group considered. The daily compensation irradiance of benthic communities ranges from 0.24 to 4.4 mol photons m−2 d−1. Data on benthic irradiance and light requirements are combined to estimate the surface area of the coastal ocean where (1) light does not limit the distribution of primary producers and (2) net community production (NCP, the balance between gross primary production and respiration) is positive. Positive benthic NCP can occur over 37% of the global shelf area. The limitations of this approach, related to the spatial resolution of the satellite data, the parameterization used to convert reflectance data to irradiance, and the relatively limited biological information available, are discussed.

scholarly journals Who gets the HANPP (Human Appropriation of Net Primary Production)? Biomass distribution and the bio-economy in the Tana Delta, Kenya

2016 ◽  
Vol 23 (1) ◽  
pp. 410 ◽  
Author(s):  
Leah Temper
Keyword(s):  
Primary Production ◽  
Political Ecology ◽  
Sugar Cane ◽  
East Coast ◽  
Net Primary Production ◽  
Social Classes ◽  
Mangrove Forests ◽  
Biomass Distribution ◽  
Plantation Economy ◽  
Induced Changes

The Tana Delta, on the east coast of Kenya near Somalia, comprises riverine mangrove forests, wetlands and rangelands and is home to a range of indigenous pastoralist, farmer and fisher communities, whose traditional multi-user livelihood strategies have helped preserve exceptional local biodiversity. This study assesses conflicts over biomass through an analysis of Human Appropriation of Net Primary Production (HANPP), an indicator used by system ecologists that quantifies human-induced changes on the productivity and harvest of biomass flows. HANPP is calculated by seeing how much of the net primary production (NPP) of biomass flows created through solar energy are appropriated by human activity, and how much is left in the ecosystems for other species. In this article we introduce calculations of the HANPP in political ecology by studying not only the distribution of biomass between humans and non-humans but also (and this is the main point) between different groups or social classes of humans. We also ask what alliances are being made to protect biodiversity and keep livelihoods intact. In a sugar cane plantation economy, biomass production and the proportion appropriated by humans may increase, the Orma pastoralists and the Pokomo farmers would be dispossessed, less biomass would be available for local 'wild' biodiversity, and a much larger proportion of the NPP would be exported as sugar or ethanol.Key words: Human appropriation of biomass; bioeconomy; biodiversity; property rights; pastoralists; sugar cane; wetlands.

scholarly journals Light availability in the coastal ocean: impact on the distribution of benthic photosynthetic organisms and their contribution to primary production

2006 ◽  
Vol 3 (4) ◽  
pp. 489-513 ◽  
Author(s):  
J.-P. Gattuso ◽  
B. Gentili ◽  
C. M. Duarte ◽  
J. A. Kleypas ◽  
J. J. Middelburg ◽  
...  
Keyword(s):  
Primary Production ◽  
Surface Area ◽  
Coastal Zone ◽  
Benthic Communities ◽  
Light Availability ◽  
Coastal Ocean ◽  
Net Community Production ◽  
Benthic Primary Production ◽  
Photosynthetic Organisms ◽  
Community Production

Abstract. One of the major features of the coastal zone is that part of its sea floor receives a significant amount of sunlight and can therefore sustain benthic primary production by seagrasses, macroalgae, microphytobenthos and corals. However, the contribution of benthic communities to the primary production of the global coastal ocean is not known, partly because the surface area where benthic primary production can proceed is poorly quantified. Here, we use a new analysis of satellite (SeaWiFS) data collected between 1998 and 2003 to estimate, for the first time at a nearly global scale, the irradiance reaching the bottom of the coastal ocean. The following cumulative functions provide the percentage of the surface (S) of the coastal zone receiving an irradiance greater than Ez (in mol photons m−2 d−1): SNon-polar = 29.61 − 17.92 log10(Ez) + 0.72 log102(Ez) + 0.90 log103(Ez) SArctic = 15.99 − 13.56 log10(Ez) + 1.49 log102(Ez) + 0.70 log103(Ez) Data on the constraint of light availability on the major benthic primary producers and net community production are reviewed. Some photosynthetic organisms can grow deeper than the nominal bottom limit of the coastal ocean (200 m). The minimum irradiance required varies from 0.4 to 5.1 mol photons m−2 d−1 depending on the group considered. The daily compensation irradiance of benthic communities ranges from 0.24 to 4.4 mol photons m−2 d−1. Data on benthic irradiance and light requirements are combined to estimate the surface area of the coastal ocean where (1) light does not limit the distribution of primary producers and (2) net community production (NCP, the balance between gross primary production and community respiration) is positive. Positive benthic NCP can occur over 33% of the global shelf area. The limitations of this approach, related to the spatial resolution of the satellite data, the parameterization used to convert reflectance data to irradiance, the lack of global information on the benthic nepheloid layer, and the relatively limited biological information available, are discussed.

Dependence of an aquatic insect population on contemporaneous primary production

2021 ◽  
Author(s):  
Joseph S Phillips ◽  
Amanda R McCormick ◽  
Jamieson C Botsch ◽  
Anthony R Ives
Keyword(s):  
Primary Production ◽  
Secondary Production ◽  
Gross Primary Production ◽  
Light Availability ◽  
Aquatic Insect ◽  
Life Cycles ◽  
Insect Emergence ◽  
Organic Matter Pool ◽  
Lake Mývatn ◽  
Internal Production

Characterizing the dynamics of energy flow through ecosystems requires quantifying the degree to which primary and secondary production are coupled. This coupling is expected to be tight in ecosystems with high internal production relative to external carbon and energy inputs. We experimentally quantified the dependence of aquatic insect emergence on fresh primary production, specifically for the midge population in Lake Myvatn, Iceland. Using field mesocosms, we manipulated algal primary production by reducing light availability via shading. We then used dissolved oxygen incubations to estimate fluxes of carbon through photosynthesis (i.e., gross primary production or "GPP") over the course of the experiment. We found that elevated GPP was associated with higher emergence rates of adults, as judged both by comparison of emergence across the experimental shading treatments and estimates of in situ GPP within the mesocosms. Furthermore, larger adults emerged earlier than smaller ones, suggesting that asymmetries in resource availability among individuals affected the timing of emergence. Nonetheless, midge emergence was substantial under light-limiting conditions, indicating that while midges benefit from primary production contemporaneous with larval development, they are also capable of completing their life cycles on carbon already existing in the organic matter pool. Our results show that even in systems with limited allochthonous inputs, contemporaneous primary production may be not necessary for high secondary production and insect emergence. Instead, consumers can develop from consumption of biomass derived from past autochthonous primary production. This suggests that primary production and consumer dynamics can be partially decoupled in time in systems that depend on internal production.

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