Newfie wrote:Dissident,
I'm trying to understand what you are getting at. What I'm hearing you say is that the sedimentation process is a negative feedback that will slow the effects of climate change?
Please clarify.
Signs that such a large decline in phytoplankton has not occurred include not observing a comparable percentage decline in fish species which feed on phytoplankton...
Another global ocean primary productivity study found a net increase in phytoplankton, as judged from measured chlorophyll, when comparing observations in 1998–2002 to those conducted during a prior mission in 1979–1986.
The airborne fraction of CO2 from human emissions, the percentage neither sequestered by photosynthetic life on land and sea nor absorbed in the oceans abiotically, has been almost constant over the past century, and that suggests a moderate upper limit on how much a component of the carbon cycle as large as phytoplankton may have declined, if such declined in recent decades.
In the example of the northeast Atlantic, a case where chlorophyll measurements extend particularly far back, the location of the Continuous Plankton Recorder (CPR) survey, there was net increase over a 1948 to 2002 period examined. During 1998–2005, global ocean net primary productivity rose during 1998 followed by primarily decline during the rest of that period, although still slightly higher at its end than at its start...
onlooker wrote:umm Dohboi , I thought Scientific American was a reputable source ,.
Newfie wrote:Sounds depressingly like the collapse of the cod fishery oh Newfoundland. That closure, 1998?, has only very recently started showing positive results.
Marine phytoplankton account for approximately half of the production of organic matter on earth, support virtually all marine ecosystems, constrain fisheries yields, and influence climate and weather. Despite this importance, long-term trajectories of phytoplankton abundance or biomass are difficult to estimate, and the extent of changes is unresolved. Here, we use a new, publicly-available database of historical shipboard oceanographic measurements to estimate long-term changes in chlorophyll concentration (Chl; a widely used proxy for phytoplankton biomass) from 1890 to 2010. This work builds upon an earlier analysis (Boyce et al., 2010) by taking published criticisms into account, and by using recalibrated data, and novel analysis methods. Rates of long-term chlorophyll change were estimated using generalized additive models within a multi-model inference framework, and post hoc sensitivity analyses were undertaken to test the robustness of results. Our analysis revealed statistically significant Chl declines over 62% of the global ocean surface area where data were present, and in 8 of 11 large ocean regions. While Chl increases have occurred in many locations, weighted syntheses of local- and regional-scale estimates confirmed that average chlorophyll concentrations have declined across the majority of the global ocean area over the past century. Sensitivity analyses indicate that these changes do not arise from any bias between data types, nor do they depend upon the method of spatial or temporal aggregation, nor the use of a particular statistical model. The wider consequences of this long-term decline of marine phytoplankton are presently unresolved, but will need to be considered in future studies of marine ecosystem structure, geochemical cycling, and fishery yields.
dohboi wrote:ScAm has fallen from its glory days. But really this is more about not placing too much weight on any one scientific study.
Repent wrote:I stopped eating all seafood after the Fukishima disaster. (You never know where the stuff comes from)
We need a 100 year moratorium on all fishing to give the oceans time to recover and to be rebalanced.
They should ban fishing and sink every boat caught fishing, that would hasten the process of recovery.
Gulf of Mexico?Repent wrote:I stopped eating all seafood after the Fukishima disaster. (You never know where the stuff comes from)
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