Bonne, W.

De Backer, A.

Devriese, L.

Hostens, K.

Van Hoey, G.

Open Marine Archive

ICES CM 2015/D:17 
The use of benthic biodiversity indicators: pros and cons  
Van Hoey Gert (1), Wendy Bonne (2), De Backer Annelies (1), Lisa Devriese (1), Kris Hostens (1)  
(1) Institute for Agricultural and Fisheries Research, Aquatic Environment and Quality, Ankerstraat 1, 
8400 Oostende, Belgium; (2) Joint Programming Initiative for Healthy and Productive Seas and Oceans, 
Troonstraat 130, 1050 Brussels, Belgium; Presenter contact details, gert.vanhoey@ilvo.vlaanderen.be; Tel. 
++32 (0) 59 56 98 47 
Summary 
Biodiversity is an important aspect in environmental management. In this contribution, we  
discuss the consequences (pros and cons) of the use of various types of benthic diversity 
indicators. Diversity is not always considered in their algorithm or in various forms, and that 
lead to a lower comparability between indicators (cf. WFD intercalibration exercise). The experts 
excluding diversity in their indicator, justifying this by the fact that diversity does not show a 
monotonic trend along gradients of pollution (cf Pearson Rosenberg model). And also when 
considering physical disturbances relationships between impact and diversity are not always 
linear, which was also the case in Belgian waters as a result of  aggregate extraction and dredge 
disposal activities. This non-linear response, however, does not hamper a consistent 
environmental assessment by benthic indicators with a biodiversity component, due to an 
adequate definition of the GES boundaries. In the near future, genetic based biodiversity 
indicators will be used alongside the classic ones, based on taxonomic species identifications. 
Genetic tools such as meta-barcoding in environmental monitoring, however, are not yet fully 
applicable, and can lead to discrepancies with the regular taxonomical approaches.  
 
Introduction 
Indicators are the scientific translation of governmental needs for reliable information on the 
condition or so-called ‘status’ of an ecosystem. Biodiversity is an important component within 
status assessments and a high-level objective of marine policy (E.g. Marine Strategy Framework 
Directive [MSFD], Water Framework Directive [WFD]). Consequently, diversity is incorporated 
into most of the indicators for the assessment of benthic ecosystem status. However, diversity is 
not always considered in their algorithm or in various forms. On this aspect and what it means 
for environmental status assessment is investigated in this contribution. 
 
Material and Method 
A large set of indicators are defined for assessing certain aspects in the status of the benthic 
habitats, as derived from the Devotool, MARMONI and WISER database. For each of those 
indicators the manner of considering biodiversity is defined in following classes: (1) not; (2) as 
number of species (or expected number of species); (3) as diversity index (E.g. Shannon, 
Simpson). The results obtained from the application of the benthic indicators in relation to their 
comparability or relationship to a pressure were derived from own studies (Van Hoey et al., 
2015; De Backer et al., 2014) or the literature (Pearson & Rosenberg, 1978; Josefson et al., 2009). 
Results and Discussion 
Fourty six indicators are assessing a certain aspect of 
the status of benthic habitats (structural, functional), 
whereof 48% a biodiversity aspect. 62% are 
operational, whereas the other part is still under 
development or conceptual. Those indicators consist 
of different algorithm types (mainly direct 
measurements or single, multimetric and multivariate 
types). Seventeen of those are operational for 
assessing the benthic status in coastal waters for the 
Water Framework Directive. Biodiversity in the WFD benthic indicators is mainly assessed by 
number of species and/or Shannon diversity (see Figure). Four of those indicators does not 
contain a diversity parameter, which was a criteria of the WFD guidance. The countries (Spain 
and France [their Mediterranean region’s], Cyprus, Greece) justified this due to the unimodal or 
no relationship of biodiversity in relation to a pressure. This duality in including or not 
including a biodiversity indicator lead to comparability problems in the WFD intercalibration, 
whereas the non-biodiversity indicators shows no or very low comparability with the 
biodiversity indicators. Therefore, the question is, is diversity really a good indicator for 
evaluating status and detecting impacts of human pressures. It is clear that diversity shows a 
relationship with pressures on the system (Pearson & Rosenberg, 1978; Josefson et al., 2009), but 
this relationship is not always straight forward. In the study of the De Backer et al. (2014), the 
effects of three impacts, i.e. sand extraction, dredge disposal and offshore wind energy 
exploitation, on the soft-bottom macrobenthic assemblages was investigated. Similar diversity-
disturbance responses, caused by sediment refinement lead to a shift towards a heterogenic, 
dynamic (transitional), more diverse soft-bottom macrobenthic assemblage in the impacted area. 
On the other hand, in severe impacted areas, the diversity declines strongly (Josefson et al., 2009; 
Van Hoey et al., 2015). These studies showed that it is not easy to use diversity as indicator. 
Classical diversity indices were widely used and form a core aspect in many benthic indicators. 
Currently, genetic tools such as meta-barcoding in environmental monitoring are upcoming. 
Diversity indicators generated from this, are not yet fully applicable, and can lead to 
discrepancies with the regular taxonomical approaches (genetic diversity higher than regular, 
cryptic species). The message is that a benthic biodiversity measure is necessary, but that this 
may not the only parameter in status assessments.  
 
References 
De Backer A, Van Hoey, G., Coates D, Vanaverbeke J, Hostens K (2014) Similar diversity-disturbance responses to 
different physical impacts: Three cases of small-scale biodiversity increase in the Belgian part of the North Sea. Marine 
Pollution Bulletin 84, 251-262 
Josefson, A.B., Blomqvist, M., Hansen, J.L.S., Rosenberg, R., and Rygg, B., 2009. Assessment of marine benthic quality 
change in gradients of disturbance: Comparison of different Scandinavian multi-metric indices. Marine Pollution 
Bulletin 58, 1263-1277. 
Pearson, T.H. and Rosenberg, R., 1978. Macrobenthic succession in relation to organic enrichment and pollution of the 
marine environment. Oceanography and Marine Biology: an Annual Review 16, 229-311. 
Van Hoey, G., Bonne, W., Salas Herrero, F., 2015. Intercalibrationreport for benthic invertebrate fauna of the North 
East Atlantic Geographical intercalibration group for Coastal Waters (NEA 1/26). ILVO mededeling 191, 79p. 
10
8
1
2
1
Diversity type
number of species
shannon
simpson
margalef
Pielou's


The use of benthic biodiversity indicators: pros and cons

http://www.vliz.be/imisdocs/publications/311284.pdf

The use of benthic biodiversity indicators: pros and cons

Abstract

Similar works

Full text

Available Versions

Open Marine Archive