Assessment of the degradation of aesthetics Beneficial Use Impairment in the Toronto and region Area of Concern

Dahmer, S. C.; Matos, Laud; Jarvie, Scott

doi:10.1080/14634988.2018.1497398

“…Morphological-based approaches, which were once the only method of determining richness, are rapidly being complemented with DNA-based methodologies such as metabarcoding, greatly increasing the taxonomic information obtained from benthic samples 21,21,[32][33][34] . In this study, we have demonstrated the benefits of Previously, morphological-based biomonitoring in Toronto Harbour had focused on overall richness as the determining factor of lake health 15,16,35 . While this can be informative as to the overall quantity of macroinvertebrate taxa present in the lake, it neglects details on the composition of taxa and proportions of bioindicator groups in relation to other taxa.…”

Section: Discussionmentioning

confidence: 77%

“…Previously, morphological-based biomonitoring in Toronto Harbour focused primarily on overall richness as the determining factor of lake health 15,16,35 with limited investigation into the composition of taxa. While this can be informative as to the overall quantity of macroinvertebrate taxa present in the lake, it misses details on the proportions of bioindicator groups in relation to other taxa.…”

Section: Discussionmentioning

confidence: 99%

Multi-marker DNA metabarcoding detects suites of environmental gradients from an urban harbour

Robinson

¹

,

Porter

²

,

McGee

³

et al. 2022

Preprint

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There is increasing need for biodiversity monitoring, especially in places where potential anthropogenic disturbance may significantly impact ecosystem health. We employed a combination of traditional morphological and bulk macroinvertebrate metabarcoding analyses to benthic samples collected from Toronto Harbour (Ontario, Canada) to compare taxonomic and functional diversity of macroinvertebrates and their responses to environmental gradients. At the species rank, sites assessed using COI metabarcoding showed more variation than sites assessed using morphological methods. Depending on the assessment method, we detected gradients in magnesium (morphological taxa), ammonia (morphological taxa, COI sequence variants), pH (18S sequence variants) as well as gradients in contaminants such as metals (COI & 18S sequence variants) and organochlorines (COI sequence variants). Observed responses to contaminants such as aromatic hydrocarbons and metals align with known patchy distributions in harbour sediments. We determined that the morphological approach may limit the detection of macroinvertebrate responses to lake environmental conditions due to the effort needed to obtain fine level taxonomic assignments necessary to investigate responses. DNA metabarcoding, however, need not be limited to macroinvertebrates, can be automated, and taxonomic assignments are associated with a certain level of accuracy from sequence variants to named taxonomic groups. The capacity to detect change using a scalable approach such as metabarcoding is critical for addressing challenges associated with biodiversity monitoring and ecological investigations.

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“…Previously, morphological-based biomonitoring in Toronto Harbour had focused primarily on overall richness as the determining factor of lake health with limited investigation into the composition of taxa 15 , 16 , 35 . While this can be informative as to the overall quantity of macroinvertebrate taxa present in the lake, it misses details on the proportions of bioindicator groups in relation to other taxa.…”

Section: Discussionmentioning

confidence: 99%

“…In 1994, eight beneficial uses in Toronto Harbour were identified as impaired (beneficial use impairments; BUIs 12 , 13 . In 1987, Toronto Harbour was designated as an Area of Concern (AOC) 13 and since then, there has been an increase in biological monitoring in the harbour 9 , 14 , 15 .…”

Section: Introductionmentioning

confidence: 99%

Multi-marker DNA metabarcoding detects suites of environmental gradients from an urban harbour

Robinson

¹

,

Porter

²

,

McGee

³

et al. 2022

Sci Rep

View full text Add to dashboard Cite

There is increasing need for biodiversity monitoring, especially in places where potential anthropogenic disturbance may significantly impact ecosystem health. We employed a combination of traditional morphological and bulk macroinvertebrate metabarcoding analyses to benthic samples collected from Toronto Harbour (Ontario, Canada) to compare taxonomic and functional diversity of macroinvertebrates and their responses to environmental gradients. At the species rank, sites assessed using COI metabarcoding showed more variation than sites assessed using morphological methods. Depending on the assessment method, we detected gradients in magnesium (morphological taxa), ammonia (morphological taxa, COI sequence variants), pH (18S sequence variants) as well as gradients in contaminants such as metals (COI & 18S sequence variants) and organochlorines (COI sequence variants). Observed responses to contaminants such as aromatic hydrocarbons and metals align with known patchy distributions in harbour sediments. We determined that the morphological approach may limit the detection of macroinvertebrate responses to lake environmental conditions due to the effort needed to obtain fine level taxonomic assignments necessary to investigate responses. DNA metabarcoding, however, need not be limited to macroinvertebrates, can be automated, and taxonomic assignments are associated with a certain level of accuracy from sequence variants to named taxonomic groups. The capacity to detect change using a scalable approach such as metabarcoding is critical for addressing challenges associated with biodiversity monitoring and ecological investigations.

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“…Edge et al, 2018). Eight of Toronto's 11 waterfront beaches are now Blue Flag beaches; Aesthetic condition of local watersheds and the Toronto waterfront are generally excellent or good, and AOC waters are free of substances that produce persistent objectionable deposits, unnatural colour or turbidity, or unnatural odours (Dahmer et al, 2018); Bottom sediments along the waterfront are getting cleaner and the health of benthic communities have improved (RAP, 2013(RAP, , 2014; Levels of contaminants in fish continue to decline and there are no restrictions on consumption of many resident fish (Bhavsar et al, 2018); Aquatic habitat improvements, including the creation and restoration of habitat for migration, spawning, nursery, feeding, shelter and overwintering support an increased diversity of fish species along the waterfront (Hoyle et al, 2018;Veilleux et al, 2018;Choy et al, 2018).…”

Section: Where We Are: Current Conditionsmentioning

confidence: 99%

Preface—Restoring Toronto’s waters: Progress toward delisting the Toronto and Region Area of Concern

Dahmer

¹

,

Matos

²

,

Morley

³

2018

Aquatic Ecosystem Health &Amp; Management

Self Cite

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In 1987, Toronto and Region (formerly Metro Toronto) was recognized as one of 43 Great Lakes Areas of Concern (AOCs) under the amended Great Lakes Water Quality Agreement (GLWQA). AOCs are locations where water quality and ecosystem health are considered to be severely degraded as a result of local sources of pollution caused by human activities that may affect the wider Great Lakes system. Under the GLWQA, the governments of Canada and the United States committed to restoring ecosystem health in the Great Lakes (IJC, 1987).Toronto and Region was identified as an AOC as a result of complex environmental challenges from several centuries of agriculture, industrialization and urban development that have dramatically reshaped the terrestrial and aquatic environments. The health of the waterfront is linked to conditions and activities in local watersheds, which provide a conduit to Lake Ontario by way of the rivers and creeksas well as storm and sanitary sewer systemsthat run through local communities.The boundary of the Toronto and Region AOC encompasses 42 km of waterfront together the north shore of Lake Ontario, along with the six watersheds from Etobicoke Creek in the west to the Rouge River in the east that drain into Lake Ontario (Figure 1). The watersheds of the AOC, which drain an area of approximately 2000 km 2 , originate from the southern slopes of the Oak Ridges Moraine (north of the City of Toronto), and are composed of more than 40% rural landuse, and contain Rouge National Urban Park, one of the world's largest national urban parks. At the same time, more than three million people live in the AOC drainage area and the City of Toronto is at the centre of one of the most densely urbanized and fastest growing areas in the Great Lakes.Historically within the AOC, a vast number of habitats have been degraded: wetlands have been drained and filled (e.g. Ashbridges Bay Marsh); forests and riverbank vegetation were removed; creeks were buried, channelized or concreted; shorelines were hardened; and dams and weirs were built that obstructed fish movement in rivers. Contaminants associated with runoff from stormwater and snow melt from local watersheds, and direct discharge of industrial and domestic wastewater, have created serious water quality impacts in local rivers, and along the waterfront. Spills, road runoff and historically unregulated chemical inputs to sewers from industries and residences contributed to a highly degraded aquatic environment.These multiple stressors polluted the local environment, impacted fish and wildlife habitats and populations (both directly and indirectly) and degraded water quality at beaches, leading to the impairment of several beneficial uses in the Toronto region, and forming the basis for the AOC designation.

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Assessment of the degradation of aesthetics Beneficial Use Impairment in the Toronto and region Area of Concern

Cited by 5 publications

References 3 publications

Multi-marker DNA metabarcoding detects suites of environmental gradients from an urban harbour

Multi-marker DNA metabarcoding detects suites of environmental gradients from an urban harbour

Multi-marker DNA metabarcoding detects suites of environmental gradients from an urban harbour

Preface—Restoring Toronto’s waters: Progress toward delisting the Toronto and Region Area of Concern

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