# Chlorophyll a, annual mean: Hobsons Bay and Central Port Phillip Bay

- Address: v/Z59Y-RA, version 1 (https://www.plot.eco/v/Z59Y-RA)
- Chart: line, Chlorophyll a (µg/L) by Year, one series per site_name_short
- Unit: µg/L
- Source: EPA Victoria (EPA Water Sciences), Port Phillip Bay Water Quality Data 1984–2026, sheet Data (s/CW7R-1A, https://www.plot.eco/s/CW7R-1A)
- Licence: CC-BY-4.0
- Stored copy: retrieved 2026-10-19, sha256 70aaa20d49aad6979a51a50165dca03e5bdb775dcedd79cdddccd2241cac4500
- Verification: reviewed by a person on 2026-10-19; computed by chart-compute/1; data sha256 d1a7a5cab434d13a30bff1a3d2b0a8d91d9dfcf924913fe9c7b59db080fbed81

Annual mean of EPA Victoria's surface water samples at two fixed sites (usually monthly). 1984 covers July to December and 2026 January to May only. An open ring marks a year in which some samples have no chlorophyll value.

Numbers are rounded to 3 decimal places; the .json has them exact.

| Year | Central | Hobsons Bay |
| --- | --- | --- |
| 1984 | 0.702 (partly missing) | 1.89 (partly missing) |
| 1985 | 1.053 | 1.823 |
| 1986 | 1.011 (partly missing) | 1.962 (partly missing) |
| 1987 | 0.403 (partly missing) | 1.81 (partly missing) |
| 1988 | 1.262 | 2.582 |
| 1989 | 1.047 | 3.001 |
| 1990 | 1.046 | 3.321 |
| 1991 | 0.77 | 2.555 |
| 1992 | 0.656 | 3.881 |
| 1993 | 1.288 | 2.238 |
| 1994 | 0.452 | 1.679 |
| 1995 | 0.817 | 3.343 |
| 1996 | 0.829 | 2.373 |
| 1997 | 0.764 (partly missing) | 2.215 |
| 1998 | 0.533 (partly missing) | 1.988 |
| 1999 | 0.801 | 2.659 |
| 2000 | 0.839 | 2.826 |
| 2001 | 1.029 | 2.992 |
| 2002 | 0.824 | 2.605 |
| 2003 | 0.622 | 1.47 (partly missing) |
| 2004 | 0.601 | 2.36 |
| 2005 | 0.583 | 1.51 |
| 2006 | 0.691 | 2.515 |
| 2007 | 0.607 | 1.591 |
| 2008 | 0.791 | 1.341 (partly missing) |
| 2009 | 0.609 | 1.491 |
| 2010 | 0.789 | 2.283 |
| 2011 | 1.781 | 3.008 |
| 2012 | 0.87 | 2.099 |
| 2013 | 0.79 | 2.15 |
| 2014 | 0.533 (partly missing) | 2.15 (partly missing) |
| 2015 | 0.403 (partly missing) | 0.72 (partly missing) |
| 2016 | 0.656 (partly missing) | 1.058 (partly missing) |
| 2017 | 0.744 (partly missing) | 1.411 (partly missing) |
| 2018 | 0.329 (partly missing) | 1.071 (partly missing) |
| 2019 | 0.462 | 0.938 |
| 2020 | 0.767 | 1.2 (partly missing) |
| 2021 | 1.038 | 1.837 |
| 2022 | 0.655 | 1.9 |
| 2023 | 0.633 | 0.956 |
| 2024 | 0.333 | 0.4 |
| 2025 | 0.486 | 1.3 |
| 2026 | 0.7 | 1.133 |

## Caveats

- Partly missing (the mean covers only the rows with a value): Central, 1984, 1 of its rows have no value; Central, 1986, 1 of its rows have no value; Central, 1987, 2 of its rows have no value; Central, 1997, 1 of its rows have no value; Central, 1998, 1 of its rows have no value; Central, 2014, 6 of its rows have no value; Central, 2015, 6 of its rows have no value; Central, 2016, 9 of its rows have no value; and 13 more (all listed in the numbers).
- Rows are combined by mean for each calendar year of date and site_name_short.
- 1613 rows left out by the filter: site_name_short is Hobsons Bay or Central.

Cite as: PLOT chart v/Z59Y-RA (version 1), Chlorophyll a, annual mean: Hobsons Bay and Central Port Phillip Bay. Data: EPA Victoria (EPA Water Sciences), Port Phillip Bay Water Quality Data 1984–2026, sheet Data (PLOT source s/CW7R-1A)