Seasonal variability in ecosystem functions: quantifying the contribution of invasive species to nutrient cycling in coastal ecosystems

Abstract

Benthic ecosystems at temperate and high latitudes experience marked seasonal variation in the environmental factors affecting nutrient remineralization processes both directly and indirectly through their effects on the benthic communities. The invasive polychaete genus Marenzelleria spp. represents new functionality in Baltic Sea sediments through its deep burrowing and extensive gallery formation, thus possibly greatly affecting the benthic oxygen and nutrient fluxes. We assessed the seasonal contribution of Marenzelleria spp. to fluxes of solutes in monthly field measurements at two sites, 10 and 33 m deep, in the northern Baltic Proper over a year. In general the fluxes of inorganic nutrients and oxygen were higher during summer than during winter and the seasonal variation was more pronounced at the deeper, more biologically active site. By using variation partitioning we were able to demonstrate that Marenzelleria and other macrofauna could account for up to 92 % of the variation in the fluxes depending on the site and season. Fauna was the most important in predicting the fluxes in spring when the sediment organic content and the abundance of juvenile Marenzelleria spp. were highest, while during e.g. winter the influence of Marenzelleria spp., even though abundant, on solute fluxes was negligible. The results from this study have implications for management, and, importantly, for the modelling of nutrient budgets often based on values from studies conducted during the summer period only, thus possibly greatly miscalculating the annual nutrient fluxes.

A Baltic Sea estuary as a phosphorus source and sink after drastic load reduction: seasonal and long-term mass balances for the Stockholm inner archipelago for 1968–2015

“…However, temperaturedependent aerobic and anaerobic microbial processes should influence O 2 consumption rates. We found seasonally increasing O 2 consumption rates from May to September or October, when the temperature increased from ∼ 2 to 9 • C. The maximum O 2 consumption rate, in September (26 mmol O 2 m −2 d −1 ), corresponds well to summer O 2 consumption rates measured in Danish estuaries (AErtebjerg et al, 2003) and Finnish archipelago areas (Kauppi et al, 2017). AErtebjerg et al (2003) found that temperature explained most of the within-year variation in O 2 consumption.…”

“…We made several sensitivity tests to check the effects of various assumptions on the results. Equations for water exchange used Knudsen's theorem for estuarine circulation (Knudsen, 1900), which assumes constant water volume (Eq. 1) and equilibrium of salt transport (Eq.…”

Instantaneous Effects of Sediment Resuspension on Inorganic and Organic Benthic Nutrient Fluxes at a Shallow Water Coastal Site in the Gulf of Finland, Baltic Sea

“…The two benthic macrofaunal taxa Macoma balthica and Marezelleria spp. that showed the highest densities among all the determined species in the experimental columns of the present study are known to affect the benthic nutrient fluxes in the study area (Kauppi et al 2017). In general, the nutrient effluxes are increased with the increasing density of fauna and increasing organic content of the sediment (Kauppi et al 2017), which is likely due to enhanced mineralization of organic material by fauna activity (Ståhl et al 2004).…”

Template for using biological trait groupings when exploring large‐scale variation in seafloor multifunctionality

“…, Kauupi et al. ). This species is known to be tolerant against disturbances and can endure low oxygen conditions (Norkko et al.…”