Anthropogenic Impacts on Marine Benthos

Study flashcards covering anthropogenic impacts on marine benthos, including stressors, resource exploitation, pollution, and solution frameworks.

What term did Jouffray et al. (2019) use to describe the expanding human demand for ocean space and resources?

The blue acceleration

According to global patterns from $2008$ to $2013$, what percentage of national jurisdictions show increased human impact?

$$77\%$$

How is a "stressor" defined in the context of marine ecosystem productivity and development?

Any physical, chemical or biological factor that requires a compensation response by affected organisms, thus placing constraints on the productivity and development of ecosystems

In the study of cumulative effects, what is the mathematical formula for an additive accumulation of impacts?

$$a\&b = a + b$$

What are the mathematical representations for synergistic and antagonistic impacts?

Synergistic is expressed as $a\&b > a + b$ and antagonistic is expressed as $a\&b < a + b$

What were the percentages of additive, synergistic, and antagonistic effects found in individual laboratory studies?

Additive ($26\%$), synergistic ($36\%$), and antagonistic ($38\%$)

What are the five major categories of human activities that result in major stresses on the ocean?

Pollution, unsustainable resource use, habitat fragmentation and destruction, species invasions, and climate change

What is

shifting baselines syndrome," a concept introduced by Pauly ($1995$)?","definition":"A phenomenon where accepted thresholds for environmental conditions continually adjust due to a lack of past information or lack of experience of past conditions"},{

Which human activity is cited as having the most extensive global footprint on the seabed?

Bottom fishing

To be economically viable, how many metric tonnes of nodules and sediment must a single mining unit process per day?

$5000$ metric tonnes of nodules and approximately $100,000$ metric tonnes of sediment

What is the potential tonnage of ore provided by the $> 20\,million\,miles^2$ of manganese nodules in the Pacific Ocean?

$$> 300\,billion\,tonnes$$

Why are manganese nodules in the Atlantic less rich in ore ($18\%$ manganese) than those in the Pacific ($20-31\%$ manganese)?

The sedimentation rate is faster in the Atlantic, leading to more sediment being mixed into the nodule and less metal concentration

How many carats of diamonds are estimated to have been eroded from land and deposited into the ocean by rivers?

$$10\,billion\,carats$$

How many carats were produced by the Marine Diamond Corporation off South Africa between November $12$, $1961$ and January $5$, $1965$?

$$361,810.55\,carats$$

When was the voluntary moratorium on dumping radioactive waste in the North Atlantic agreed?

$$1983$$

What is the half-life of the radioactive isotope $^{241}Am$ used in bioavailability experiments by Vangenechten et al. ($1983$)?

$$432\,years$$

At what depth was $^{134}Cs$ from the Chernobyl accident found in the Barents Sea by $1987$?

$$> 1000\,m$$

Where was Deepwater Municipal Dump Site $106$ (DWD106) located, and how much sewage was discharged annually between $1986$ and $1992$?

$106\,nautical\,miles$ off New York City; approximately $8\,million\,tons$ annually

What three tracers were used to track where sewage from DWD106 settled on the seafloor?

Silver (from photographic/electronic industries), alkylbenzenes (from detergents), and spores from Clostridium perfringens (from faecal material)

Which two benthic species were identified as entering the benthic food web through surface-deposit feeding on sewage at DWD106?

The urchin Echinus affinus and the sea cucumber Benthodytes sanguinolenta

In surveys conducted between $1992$ and $2017$, what was the observed range of litter abundance on the UK seafloor?

$0$ to $1835\,pieces\,km^{-2}$

How does nutrient loading from agriculture disrupt the natural balance of marine systems?

It disrupts the balance between $N_2$ fixation and denitrification, leading to nitrogen accumulation and eutrophication which results in hypoxia

According to Lloyds register for $1971-1990$, what was the average number of ships and the gross tonnage lost per year?

$185\,ships$ and $643,000\,tonnes$

What are "rusticles" that form on shipwrecks, and what can they consist of?

Metal eaten away by bacteria and fungi, consisting of iron oxides and high levels of toxic metals and metalloids from ship paint

What temperature can renewable power cables reach on the seafloor?

$$> 100^\circ C$$

At what depth and temperature does $CO_2$ turn into its liquid phase for sequestration?

At depths $> 500\,m$ when temperatures are $> 11^\circ C$

What was the mortality rate for benthic copepods exposed to liquid $CO_2$ in Thistle et al. ($2007$) experiments?

$$\sim 80\%$$

What historical period and duration are used as the baseline for the Planetary Boundaries concept?

The Holocene, which is the last $11,000\,years$

What are "Seeds" in the context of a "Good Anthropocene"?

Social, technological, economic, or social–ecological ways of thinking or doing

What is the umbrella concept of "Nature-based Solutions" intended to achieve?

To collectively use the features and complex system processes of ecosystems to achieve multiple benefits for nature, the economy, and society