Frequency of ice scour events limiting maximum macroalgal cover

Ascertain the frequency and temporal distribution of ice scour events—collisions of sea ice with the sea floor and/or substrate—in Antarctic shallow-water benthic habitats to quantify how often these disturbances occur and thus assess their role in limiting the maximum attainable macroalgal cover (carrying capacity).

Background

In discussing why estimated maximum macroalgal cover (carrying capacity) may not reach 100%, the paper highlights physical disturbances such as ice scour as a plausible limiting process. Ice scour involves collisions of ice with the seabed that can repeatedly clear benthic fauna before full cover is reached.

However, the authors explicitly note that the frequency of such scouring events is not clear from existing evidence. Determining this frequency is important for understanding constraints on macroalgal carrying capacity and for improving ecological models that predict community composition under changing sea-ice regimes.

References

Potential processes for limiting the maximum algae cover could include, for example, ice scour from bodies of ice colliding with the sea floor and/or substrate \citep{Barnes1999, Peck1999, Brown2004, Johnston2007, Smale2007, Barnes2011}, whereby continual collisions repeatedly clear fauna prior to it reaching full cover, although it is not clear how frequently this process occurs \citep{Barnes1999, Brown2004}.

— A generalised sigmoid population growth model with energy dependence: application to quantify the tipping point for Antarctic shallow seabed algae  (2403.15002 - Mills et al., 2024) in Discussion, Section 'Predicting the maximum cover, and rate of change in cover, of Antarctic algae' (Section 5.4)