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. Author manuscript; available in PMC: 2019 Sep 18.
Published in final edited form as: Front Mar Sci. 2018;5:10.3389/fmars.2018.00422. doi: 10.3389/fmars.2018.00422

TABLE 1 |.

Estimated attainment deficit (initial and current status) and associated statistical resultsa for Chesapeake Bay dissolved oxygen criterion for the three designated uses, four salinity zones, and thirteen tidal systems.

Subgroup Initial deficit
(1985–1987),
percent
Current deficit
(2014–2016),
percent
Change point
(3-year period)
30-cycle trend,
percent/year
15-cycle trend,
percent/year

All segments and DUs (TOTAL) −5.5 −4.3 2010–2012 - 0.01 - 0.10 -
Designated use
Open water (OW) −1.6 −0.8 1994–1996 *** 0.04 * 0.02 -
Deep water (DW) −4.1 −3.2 2009–2011 - 0.00 - 0.13 -
Deep channel (DC) −17.9 −15.2 1990–1992 - −0.03 - 0.24 -
Salinity zone
Tidal fresh (TF) −2.0 −1.4 2000–2002 - −0.01 - 0.13 -
Oligohaline (OH) −3.3 −1.6 2005–2007 * 0.04 * 0.15 ***
Mesohaline (MH) −7.1 −6.0 2009–2011 - −0.01 - 0.14 -
Polyhaline (PH) −1.6 −0.2 1995–1997 *** 0.07 * −0.03 -
Tidal system
Chester (CHES) −3.3 −1.8 1987–1989 - 0.06 - 0.16 -
Choptank (CHOP) −0.5 −0.5 1997–1999 *** −0.07 - 0.31 ***
Elizabeth (ELIZ)b −24.1 −22.6 1991–1993 * −0.24 - −0.53 ***
James (JAME) −0.8 −0.3 1992–1994 - 0.00 - 0.07 *
Mainstem Bay (MAIN) −5.6 −4.8 2009–2011 - 0.02 - 0.09 -
Nanticoke (NANT) −1.1 −0.3 1998–2000 * −0.01 - 0.55 ***
Patuxent (PATU) −10.7 −2.2 2006–2008 - 0.08 - 0.98 ***
Pocomoke (POCO) −4.2 −4.2 2003–2005 *** 0.07 - 0.23 *
Potomac (POTO) −6.0 −3.5 1995–1997 - −0.07 - 0.19 -
Rappahannock (RAPP) −7.4 −3.9 1996–1998 * 0.10 - −0.29 -
Tangier (TANG) −0.2 −0.7 2002–2004 - −0.01 - −0.05 -
Upper mainstem Bay tributaries (UPPE) −9.6 −6.0 2010–2012 - 0.03 - 0.17 -
York (YORK) −9.4 −10.0 2003–2005 *** 0.15 *** 0.04 -
a

Significance levels are provided next to each estimate:

(***)

p < 0.05

(*)

0.05 < p < 0.1

(-)

p > 0.1.

b

Elizabeth does not have data in 1985–1987 or 1986–1988, so the earliest period with data (i.e., 1987–1989) was used to represent its initial deficit status.